Climate of the United States

[NC_Palms]

I created my own climate classification map, since I find the majority of the other ones flawed. With the creation of this map, I considered both temperature and flora of a region. Please feel free to add your own 2¢. 

 

Cool Temperate Deciduous/Mixed Forest: Cold winter and mild summer climate. Occupies the Northern tier of the country from New England to California. Eastern Section is predominantly mixed while the Western section is more coniferous.     

Warm Temperate Deciduous/Mix Forest: Cold winter and a hot summer climate. Located south of the cool temperates. More Deciduous than the cool temperates except in Southern NJ, Long Island and in the piedmont of the Southeast; where it makes way to a warmer coniferous forest.  

Temperate Rainforest: Mild climate year round with heavy rainfall. Found alongside the Pacific coast from California to Alaska. Also found in the Southern Appalachians. 

Temperate Steppe: Not enough rainfall in the Midwest stops tall trees from the deciduous forest to prosper, Thus creating a grassland system. 

Temperate Arid: Cold winter and hot summer desert biome. 

Subtropical Arid: Hot year round. Always occupied by the subtropical highs. 

Subtropical Steppe: Similar to the temperate steppe, plants from the humid subtropics won't grow where rainfall is lesser.

Subtropical Coniferous: Mild winter and Hot humid summer climate. Boundaries of this biome follow the ranges of the longleaf and slash pine flatwoods and cypress bottomlands.  

Tropical Broadleaf: Hot climate with little seasonal variation. Found in Hawaii and the coastlines of South Florida. The Everglades and the interior of South Florida are transitional between subtropical coniferous and tropical broadleaf    

Warm Mediterranean: A dry hot summer and mild winter subtropical climate. Found in the Southern California coast. 

Cool Mediterranean: Dry warm summer and mild winter temperate climate. Transitional climate of the rainier Pacific northwest and the hotter and dryer Southern California.

Subarctic: Mild summer and frigid winter climate. Found throughout Alaska and in high mountain peaks in the Continental United States.

Tundra:  Transitional climate between ice capped and subarctic. Found in Northern Alaska and high continental American peaks. 

 

 

When making the map I did not put extreme weather into account. Once in a couple hundred of years a cold blast may be sent all the way to the Bahamas and to the Florida Keys. Temperatures below 50º for a long enough time in South Florida will kill native flora. Even seeing temperatures below 10º in Eastern North Carolina would damage and defoliate our native plants. This is why taking native flora is important in climate classification. 

 

 

 

 

 

 

 

 

 

Edited June 18, 2018 by NC_Palms

[kinzyjr]

Pretty interesting map.  The light green following the Mississippi north is a pattern I hadn't seen used before, but if there are places in Missouri where sabal minor or rhapidophyllum hystrix could naturalize, that's where I think it would be.

[Austinpalm]

Southwest of Houston, the Subtropical Coniferous becomes Subtropical Savanna. Rainfall and pines decrease while grass cover increases. 

[NC_Palms]

18 hours ago, kinzyjr said:

Pretty interesting map.  The light green following the Mississippi north is a pattern I hadn't seen used before, but if there are places in Missouri where sabal minor or rhapidophyllum hystrix could naturalize, that's where I think it would be.

Thanks. I classified the the lower Mississippi floodplain as subtropical coniferous because the region is predominately bald cypress bottomland forest, with a mild winter and a hot and humid summer. The coniferous bottomland forest won't extend north of the Missouri boot, where the winters gets too cold to be considered subtropical. 

[NC_Palms]

18 hours ago, Austinpalm said:

Southwest of Houston, the Subtropical Coniferous becomes Subtropical Savanna. Rainfall and pines decrease while grass cover increases. 

You're right! I think I may of extended the subtropical coniferous forest biome too far west into Texas. The subtropical savanna biome should take up the majority of South Texas. 

[Austinpalm]

5 hours ago, NC_Palms said:

You're right! I think I may of extended the subtropical coniferous forest biome too far west into Texas. The subtropical savanna biome should take up the majority of South Texas. 

I think starting the savanna biome south of a line from Houston to San Antonio would be appropriate. 

[mdsonofthesouth]

In the Peidmont of Maryland we are still meeting humid subtropical standards. Or is your version higher in the winter than the koppen?

 

Our lows are high 20s to low 30s and highs are over 40 for the coldest months. But the coniferus zone does fade to a mix of deciduous and coniferus. Loblolly is cultivated to the foothills at the very least and is endemic to at least western Howard county in small pockets. Were loblooly fades short leaf starts to pick up. We have naturalized magnolia granfloria, yucca gloriosa (and pretty much any yucca...), needle and sabal minor (to a much lesser extent). Going find the trachycarpus that will do so hopefully before my time is over here!

 

Pretty cool map though.

[TexasColdHardyPalms]

Way too much green south and west of houston. That line should be about 30 miles east of dallas and go straight down to the west side of houston

[PalmatierMeg]

I disagree that mainland SFL (excluding, perhaps, the Keys) meets the criteria of true Tropical. While that may be true much of the year, winters are distinctly colder and drier than in the true tropics. That is because all of FL is vulnerable to Arctic influences that can drive unhindered the length of the peninsula every winter and lower temps to the 40s and occasionally the 30s down to freezing.

[NC_Palms]

On 19/6/2018 10:29:46, mdsonofthesouth said:

In the Peidmont of Maryland we are still meeting humid subtropical standards. Or is your version higher in the winter than the koppen?

 

Our lows are high 20s to low 30s and highs are over 40 for the coldest months. But the coniferus zone does fade to a mix of deciduous and coniferus. Loblolly is cultivated to the foothills at the very least and is endemic to at least western Howard county in small pockets. Were loblooly fades short leaf starts to pick up. We have naturalized magnolia granfloria, yucca gloriosa (and pretty much any yucca...), needle and sabal minor (to a much lesser extent). Going find the trachycarpus that will do so hopefully before my time is over here!

 

Pretty cool map though.

My version of a humid subtropical climate has a slightly warmer winter then Köppen and follows the ranges of common flora. Thus this would include Maryland’s Delmarva and the extreme Western Shore. Central Maryland and the piedmont can be a transitional zone between temperate deciduous and subtropical coniferous, since it lies primarily in the Southeastern mixed forest ecoregion. 

I used to live not too far from Central Maryland (in Pennsylvania). Central Maryland’s forest are more similar to Lancaster or Adams county, Pennsylvania then it is to Worcester or Somerset county, Maryland. The Delmarva’s cypress bottomlands and hammocks are more similar to Virginia Beach or Currituck County, North Carolina then the interior of Maryland. 

 

Otherwise, where are there sabal minor and palms naturalized in Maryland? 

[NC_Palms]

1 hour ago, PalmatierMeg said:

I disagree that mainland SFL (excluding, perhaps, the Keys) meets the criteria of true Tropical. While that may be true much of the year, winters are distinctly colder and drier than in the true tropics. That is because all of FL is vulnerable to Arctic influences that can drive unhindered the length of the peninsula every winter and lower temps to the 40s and occasionally the 30s down to freezing.

The map doesn’t show it but I only consider the coastlines of South Florida to be tropical. The inland counties are more distinctly coniferous unlike the coastal broadleaf forest. 

[NC_Palms]

5 hours ago, TexasColdHardyPalms said:

Way too much green south and west of houston. That line should be about 30 miles east of dallas and go straight down to the west side of houston

Thanks for informing me. I don’t know to much about Texas compared to the Atlantic states. 

[mdsonofthesouth]

5 hours ago, NC_Palms said:

My version of a humid subtropical climate has a slightly warmer winter then Köppen and follows the ranges of common flora. Thus this would include Maryland’s Delmarva and the extreme Western Shore. Central Maryland and the piedmont can be a transitional zone between temperate deciduous and subtropical coniferous, since it lies primarily in the Southeastern mixed forest ecoregion. 

I used to live not too far from Central Maryland (in Pennsylvania). Central Maryland’s forest are more similar to Lancaster or Adams county, Pennsylvania then it is to Worcester or Somerset county, Maryland. The Delmarva’s cypress bottomlands and hammocks are more similar to Virginia Beach or Currituck County, North Carolina then the interior of Maryland. 

 

Otherwise, where are there sabal minor and palms naturalized in Maryland? 

 

Rhapidophyllum hystrix has been harvested here for many decades, sabal minor is close in hardiness and is grown here and there. Both grow in most of the state without protection. It's rare that we see zone 7 temps and unless it's a freak year like this past winter it's only for brief periods. Well within the safe zone for both.

 

Trachycarpus, I think, could be naturalized or at least bulletproof in the tidewater or eastern shore areas. There is a neglected one in oc that's as tall as the building its next to it and it's been neglected. 

 

As for your climate definition that makes sense as in the Piedmont southern yellow are still there, but they aren't the only tree like on delmarva or parts of tidewater and SOMD. 

[Austinpalm]

On ‎6‎/‎20‎/‎2018‎ ‎6‎:‎39‎:‎45‎, TexasColdHardyPalms said:

Way too much green south and west of houston. That line should be about 30 miles east of dallas and go straight down to the west side of Houston

While not perfect, I generally agree with the extent of green north of Houston, after all, the Lost Pines reach west nearly to Austin and San Antonio.

[jimmyt]

NC_Palms,

      100%  correct or not,  I give you a big BOOYAH! just for creating this map.

jimmyt

[LF-TX]

3 hours ago, jimmyt said:

NC_Palms,

      100%  correct or not,  I give you a big BOOYAH! just for creating this map.

jimmyt

I agree! Very well thought out map.  I cant comment much about other areas of our country but my 2¢ is regarding the Rio Grande Valley in deep S. Texas. Longleaf / slash pine and crypress bottomlands are almost entirely absent in our area. Not completely in a subtropical coniferous climate, but not completely in a tropical broadleaf climate. Hahaha who will ever understand the RGV. The RGV is a generally dry region but wet spells like the one that just happened this week completely drench us, very weird climate.

[Palm crazy]

57 minutes ago, LF-TX said:

I agree! Very well thought out map.  I cant comment much about other areas of our country but my 2¢ is regarding the Rio Grande Valley in deep S. Texas. Longleaf / slash pine and crypress bottomlands are almost entirely absent in our area. Not completely in a subtropical coniferous climate, but not completely in a tropical broadleaf climate. Hahaha who will ever understand the RGV. The RGV is a generally dry region but wet spells like the one that just happened this week completely drench us, very weird climate.

For the PNW at least W.WA would be Temperate Rainforest along the coast - and a little inland.

The rest of W.WA would be Cool Mediterranean...rainy winters with mostly dry summers.

E.WA upper state Cool Temperate.

S.WA (eastern side) Cool Arid with only 6" of rain annually. 

Edited June 22, 2018 by Palm crazy

[pin38]

Just curious, what GIS software did you use? I like how you did it by county; obviously there's shortfalls but it's probably the best without spending a ton of time and/or money

[Austinpalm]

20 hours ago, LF-TX said:

I agree! Very well thought out map.  I cant comment much about other areas of our country but my 2¢ is regarding the Rio Grande Valley in deep S. Texas. Longleaf / slash pine and crypress bottomlands are almost entirely absent in our area. Not completely in a subtropical coniferous climate, but not completely in a tropical broadleaf climate. Hahaha who will ever understand the RGV. The RGV is a generally dry region but wet spells like the one that just happened this week completely drench us, very weird climate.

I was wondering if a narrow strip from Brownsville to Boca Chica might qualify as tropical?

[Xerarch]

2 hours ago, Austinpalm said:

I was wondering if a narrow strip from Brownsville to Boca Chica might qualify as tropical?

Brownsville misses a tropical classification by only a few degrees.  To be tropical, take the coldest month of the year, the average temperature for that month (averaged between the high and low) must be 64.4 degrees F (18 C) or above. The average in Brownsville in January is about 61 putting it on the very warm end of sub-tropical. 

But on the warm years it does cross the threshold and you can have periods of tropical temperatures, but the overall average across many years will not be officially tropical. 

[NC_Palms]

On 6/21/2018, 5:45:58, jimmyt said:

NC_Palms,

      100%  correct or not,  I give you a big BOOYAH! just for creating this map.

jimmyt

Thank you so much! 

[NC_Palms]

On 6/21/2018, 9:41:04, LF-TX said:

I agree! Very well thought out map.  I cant comment much about other areas of our country but my 2¢ is regarding the Rio Grande Valley in deep S. Texas. Longleaf / slash pine and crypress bottomlands are almost entirely absent in our area. Not completely in a subtropical coniferous climate, but not completely in a tropical broadleaf climate. Hahaha who will ever understand the RGV. The RGV is a generally dry region but wet spells like the one that just happened this week completely drench us, very weird climate.

Thank you. I am not too familiar with too much with Texas but I am planing on making a new map in the future to fix up the Rio Grande Valley. 

[NC_Palms]

11 hours ago, pin38 said:

Just curious, what GIS software did you use? I like how you did it by county; obviously there's shortfalls but it's probably the best without spending a ton of time and/or money

I used MapChart.net. The only problem with the county version is that almost all climatic regions and biomes cross over counties. For instance, I only consider the coastal regions of South Florida to be considered tropical broadleaf. The interior of South Florida would be considered subtropical coniferous and is much more similar to the Carolinas than to the Bahamas. Otherwise I could not make these distinctions on the county version. 

[NC_Palms]

 

7 hours ago, Austinpalm said:

I was wondering if a narrow strip from Brownsville to Boca Chica might qualify as tropical?

Technically that strip would classify as subtropical steppe, almost bordering a true tropical climate. I should've extended the Subtropical Steppe into that region.   

[NC_Palms]

On 6/20/2018, 6:01:15, mdsonofthesouth said:

 

Rhapidophyllum hystrix has been harvested here for many decades, sabal minor is close in hardiness and is grown here and there. Both grow in most of the state without protection. It's rare that we see zone 7 temps and unless it's a freak year like this past winter it's only for brief periods. Well within the safe zone for both.

 

Trachycarpus, I think, could be naturalized or at least bulletproof in the tidewater or eastern shore areas. There is a neglected one in oc that's as tall as the building its next to it and it's been neglected. 

 

As for your climate definition that makes sense as in the Piedmont southern yellow are still there, but they aren't the only tree like on delmarva or parts of tidewater and SOMD. 

In North Carolina our native populations of sabal minors got damaged from this past winter. I wonder how they did up in Maryland. 

[mdsonofthesouth]

Not sure as they aren't common. But our temps aren't fatal for their fronds let alone killing them, although the period under 32f was pretty rough. Debating making a scrub of yucca, rhapidophyllum and sabal minor on the colder side of the house. Will replace unprotected trachycarpus that succumb with needle or minor and weave yucca in between and see what happens.

[Austinpalm]

On ‎6‎/‎22‎/‎2018‎ ‎7‎:‎19‎:‎27‎, Xerarch said:

Brownsville misses a tropical classification by only a few degrees.  To be tropical, take the coldest month of the year, the average temperature for that month (averaged between the high and low) must be 64.4 degrees F (18 C) or above. The average in Brownsville in January is about 61 putting it on the very warm end of sub-tropical. 

But on the warm years it does cross the threshold and you can have periods of tropical temperatures, but the overall average across many years will not be officially tropical. 

If this is an average of a 30 year period, than that January average may be coming up in the next few years as the cold 1980's will be dropped.

On ‎6‎/‎22‎/‎2018‎ ‎11‎:‎58‎:‎48‎, NC_Palms said:

 

Technically that strip would classify as subtropical steppe, almost bordering a true tropical climate. I should've extended the Subtropical Steppe into that region.   

Does steppe mean something different climatologically than it does biologically.  While there are grass dominated areas in South Texas and LRGV, there is a significant shrub and tree component, especially along the river.  I would think the Subtropical  Savanna would be more correct, but perhaps that is not an option.

[Nj Palms]

You should add pinelands to Ocean County in Nj and eastern areas of Long Island!Its definitely different from the rest of the state many exotic plants such as sundew and other carnivorous plants and dwarf pine forest can be found!I even have carnivorous plants and a lady slipper orchid in a bog environment right down my street!

[Nj Palms]

3 hours ago, Austinpalm said:

If this is an average of a 30 year period, than that January average may be coming up in the next few years as the cold 1980's will be dropped.

Does steppe mean something different climatologically than it does biologically.  While there are grass dominated areas in South Texas and LRGV, there is a significant shrub and tree component, especially along the river.  I would think the Subtropical  Savanna would be more correct, but perhaps that is not an option.

Steppe enviroment would be west of Laredo.Starting south of Houston all the way down to the Rio Grande is grassland dominated by mesquite and some scrub bushes.But along and close to the river more plants can be found so I would consider it subtropical savanah.

[Nj Palms]

On 6/23/2018, 1:01:27, NC_Palms said:

In North Carolina our native populations of sabal minors got damaged from this past winter. I wonder how they did up in Maryland. 

What temp did it get down to?

[NC_Palms]

On 6/25/2018, 1:15:12, Nj Palms said:

You should add pinelands to Ocean County in Nj and eastern areas of Long Island!Its definitely different from the rest of the state many exotic plants such as sundew and other carnivorous plants and dwarf pine forest can be found!I even have carnivorous plants and a lady slipper orchid in a bog environment right down my street!

Agreed! The New Jersey Pine Barrens and the coniferous coastlines of Long Island are separate from the temperate deciduous forest. North of the Delaware Bay it gets too cold for the subtropical coniferous forest biome and too oceanic for a deciduous biome, thus giving the perfect conditions for a temperate coniferous forest biome. 

On 6/25/2018, 1:18:59, Nj Palms said:

What temp did it get down to?

January was extremely below average for us, with low temperatures between 5º and -1º. Average January lows are in the low 30's. 

[mdsonofthesouth]

Lowest we got was 3f where it's rare to go below 15f and the average low is 27 to 29f. This past winter was a freak for sure and this el nino talk has me worried about 2018/19....

[PalmTreeDude]

Well my county still stayed as Subtropical. I agree with this map for the most part other than a few areas and the Subtropical climate does seem to follow the Mississippi River. 

Edited July 1, 2018 by PalmTreeDude
Spelling Errors

[NC_Palms]

On 7/1/2018, 10:58:01, PalmTreeDude said:

Well my county still stayed as Subtropical. I agree with this map for the most part other than a few areas and the Subtropical climate does seem to follow the Mississippi River. 

What few areas do you disagree with? I'm just curious since I am aware that I made a few mistakes when creating the map. 

[NC_Palms]

On 6/28/2018, 12:12:05, mdsonofthesouth said:

Lowest we got was 3f where it's rare to go below 15f and the average low is 27 to 29f. This past winter was a freak for sure and this el nino talk has me worried about 2018/19....

Your climate in Maryland is quite similar to Eastern North Carolina. In Pitt County our average January Lows are around 30f with the coldest temperatures rarely going below 18f. What region of Maryland are you in exactly? Around the bay and in the Delmarva, the state definitely meets the qualifications of subtropical.

[PalmTreeDude]

12 hours ago, NC_Palms said:

What few areas do you disagree with? I'm just curious since I am aware that I made a few mistakes when creating the map. 

They are super little details. For example I would probably consider Choctaw and Bryan county (West of McCurtain in Oklahoma) subtropical. Also for Hot Arid I would probably highlight all of Southern Arizona because it gets crazy hot there. 

[mdsonofthesouth]

On 7/18/2018, 9:40:49, NC_Palms said:

Your climate in Maryland is quite similar to Eastern North Carolina. In Pitt County our average January Lows are around 30f with the coldest temperatures rarely going below 18f. What region of Maryland are you in exactly? Around the bay and in the Delmarva, the state definitely meets the qualifications of subtropical.

 

I am in the peidmont near the fall line. Here are the temperature averages, pretty sure the last 6 to 8 years has dropped our January low from 27 to 25, but overall we will classify well into Koppen humid subtropic. But in fact are not full coniferus humid subtropic like all of delmarva and tidewater MD and VA. We have a whole mess of shortleaf and scattered loblolly but the dominate pines are shortleag and eastern white sadly. Where I was in Colombia was filled with strands of loblolly.

My goal on my property is to have 1 to 2 pine groves setup and see if they can reproduce. Goal is to have slash, longleaf and loblooly and see what happens!

 

[PalmTreeDude]

11 hours ago, mdsonofthesouth said:

 

I am in the peidmont near the fall line. Here are the temperature averages, pretty sure the last 6 to 8 years has dropped our January low from 27 to 25, but overall we will classify well into Koppen humid subtropic. But in fact are not full coniferus humid subtropic like all of delmarva and tidewater MD and VA. We have a whole mess of shortleaf and scattered loblolly but the dominate pines are shortleag and eastern white sadly. Where I was in Colombia was filled with strands of loblolly.

My goal on my property is to have 1 to 2 pine groves setup and see if they can reproduce. Goal is to have slash, longleaf and loblooly and see what happens!

 

If you plant Loblollys in the ground (from seedling) after the first two years it is like they hit a growth spurt and just become huge. At least that is what I have found with them here. Some people here remove them because they see them as weeds but I love them. 

[NC_Palms]

 

20 hours ago, mdsonofthesouth said:

 

I am in the peidmont near the fall line. Here are the temperature averages, pretty sure the last 6 to 8 years has dropped our January low from 27 to 25, but overall we will classify well into Koppen humid subtropic. But in fact are not full coniferus humid subtropic like all of delmarva and tidewater MD and VA. We have a whole mess of shortleaf and scattered loblolly but the dominate pines are shortleag and eastern white sadly. Where I was in Colombia was filled with strands of loblolly.

My goal on my property is to have 1 to 2 pine groves setup and see if they can reproduce. Goal is to have slash, longleaf and loblooly and see what happens!

 

Along the Chesapeake bay in Maryland’s western shore, loblolly pines are quite abundant. It’s rare to find loblolly pines farther up than maybe Baltimore. Pond pines, bald cypress and white cedar are some of the other conifers found among Maryland’s loblolly pines. Eastern white pine isn’t native to the majority of Maryland’s piedmont and coastal regions. The tree stops growing naturally in extreme southern Pennsylvania but has been naturalized throughout the Middle Atlantic. 

The immediate coastline of the Chesapeake bay near the Annapolis area andsouth are considered apart of the subtropical coniferous forest. 

8 hours ago, PalmTreeDude said:

If you plant Loblollys in the ground (from seedling) after the first two years it is like they hit a growth spurt and just become huge. At least that is what I have found with them here. Some people here remove them because they see them as weeds but I love them. 

The longleaf pine is the real tree of the South! Before colonialism the longleaf pine flatwoods blanketed the majority of the subtropical coniferous forest. Nowadays the flatwoods are rare, urbanization and farming depleted the dominate ecosystem. In the Carolinas and Virginia, loblolly pines and many deciduous trees have taken over. Beforehand their growth was limited by annual fires, which no longer naturally occur. Let fires happen naturally again and the longleaf pine will redominate. 

[Dave-Vero]

There's been significant academic work on climate in recent years.  BTW, this NOAA interactive climate data page is fun to play with.  The seasonal distribution of rain in Florida is interesting--switching from west to east coast during the summer.    https://www.ncdc.noaa.gov/climateatlas/