What's Up With Costal Southern California VS Inland Southern California?

[PalmTreeDude]

Is this huge difference in tempatures in Coastal Southern California and Inland Southern California from the ocean and the mountains? How high are these mountains? Every time I look at a tempature map of the U.S. I see how much cooler it is in Coastal California than Inland California, which I know is a desert. Does Coastal California ever seem chilly out at some times around this time of year? Out of curiosity I sometimes compare tempatures of here and places like San Diego or Los Angeles and a lot of the time it is warmer here (during the day) in the Spring time. For people who live in these places, what does it feel like out? It looks like Southern California has all kinds of different little (but bigger than micro) climates. I make sure to pay attention to the time difference as well. 

I apologize for the typo in the title, I didn't notice it. 

 

Edited May 16, 2019 by PalmTreeDude

[Chris Chance]

Really the ocean has a lot to do with that. Closer to the ocean the cooler and more mild it gets. Basically if you're within 30 miles or so depending on mountains and current you would get an influence from the sea. I'm pretty far inland myself but I still get an influence. If I head east even 10 miles there's a big difference in climate. 

[Hammer]

That pretty well sums it up.  The hills and mountains create a big blocking factor.  Even hills a few hundred feet high can block and channel cool ocean breezes.  The pockets behind those hills can be a lot warmer.  

I am 6 miles from the coast.   I get a fair amount of ocean influence but am blocked by a set of coastal hills.  Irvine is further inland but the flat terrain there often times allows for cooler temps than where I live.  San Juan Capistrano also has some very distinct features like this.

On a less dramatic level, elevation can play a role too.  

[Walt]

Other than a mountain range basically blocking off a cold or hot air mass, a large body of water is probably the biggest single factor driving land temperatures in proximity of it.

Just days ago, a high pressure system north of Florida (with clockwise winds) was steadily blowing cooler Atlantic Ocean air from east to west across the peninsula.  As such, daily air temperatures (at the height of the day's heating) were running 8-9 degrees cooler on the Atlantic coast than deep inland at the same latitude. Of course, at night fall these same locations on the coast will have a higher nighttime temperature than the same points inland (since ground cools off faster than water; and just the opposite during the day). This can be unpleasant during the summer months (hotter at night), but very beneficial during the winter, as coastal area are warmer and less prone to a freeze/frost.

Right now the water temperature off Clearwater Beach, Florida, is 87 degrees F -- and it's not even June yet!

With respect to California, coastal water temperatures relatively cool. LIttle wonder the coastal areas are cooler than farther inland, especially when the wind is coming off the water.

Check the California coastal water temperatures at below link:

https://www.currentresults.com/Oceans/Temperature/pacific-ocean-temperature-california-summer.php

 

 

[BS Man about Palms]

I live 1.5 miles off the coast in northern San Diego county and in addition to the cooler coastal temps, there can be an extreme humidity difference too. The cool Pacific influence will raise humidity drastically nearby.., but further away, not so much.  During the summer it is not unusual at all for me to be driving home on a hot summer day from inland and essentially see a giant fog bank rising hundreds of feet up coming 1-2 miles inland. Very often, if not almost all the time my humidity can be 20-25% higher than 8-10 miles inland.  This makes the heat needed for growth sparse... HOWEVER the humidity here makes growing most New Cal palms a breeze!!

[GottmitAlex]

Agreed. My office is in Otay mesa, San Diego it's 14 miles inland. Just as an example: I left my office today to see a customer in National city.(coastal side)

It is sunny and quite hot in Otay, once I hit the 5 freeway (coastal north/south fwy) it was foggy, cloudy and 10f cooler than Otay mesa. 

That is usually the case 10+ miles inland California. But of course, there is a certain threshold: you go too far inland and you'll have to climb. You'll hit 9b- zones.  Imho, ideally in Commifornia: 500ft or lower altitude.

 

Edited May 30, 2019 by GottmitAlex

[PalmTreeDude]

Can you guys swim in outdoor pools in the Spring in Southern Coastal California without feeling cold? We got hot so fast here I went swimming in early May and the water already felt warm (non heated pool). 

[James B]

On 6/4/2019 at 5:23 PM, PalmTreeDude said:

Can you guys swim in outdoor pools in the Spring in Southern Coastal California without feeling cold? We got hot so fast here I went swimming in early May and the water already felt warm (non heated pool). 

Only if the pool is heated. Otherwise it’s probably sitting between 60-65 degrees.

The Pacific is a much larger and colder ocean than the Atlantic and creates a completely different climate as a result. I lived in the Orlando area growing up and the ocean temps between the coasts can be 20 degrees different sometimes. The cool marine layer the Pacific puts out travels down the San Gabriel Mountains all the way to me in spring, winter, etc. I am between 50-55 miles inland as the crow flies to give you an idea of how much the Pacific can impact the area.

Edited July 28, 2019 by James B

[BS Man about Palms]

Also to add, the Pacific is a MUCH cooler ocean than others, so it ends to regulate to the cool side.. thus Hurricanes, etc. are extremely rare.  Right now we are having our "monsoonal" influence which is bring weather from the south with it's much warmer water and raising overall humidity drastically... (and makes for afternoon thunderstorms in the mountains!

 

 

[Gonzer]

On 6/4/2019 at 5:23 PM, PalmTreeDude said:

Can you guys swim in outdoor pools in the Spring in Southern Coastal California without feeling cold? We got hot so fast here I went swimming in early May and the water already felt warm (non heated pool). 

None of us are rich enough to afford an indoor pool.

[Silas_Sancona]

On 6/4/2019 at 5:23 PM, PalmTreeDude said:

Can you guys swim in outdoor pools in the Spring in Southern Coastal California without feeling cold? We got hot so fast here I went swimming in early May and the water already felt warm (non heated pool). 

Spent a good amount of my younger / Highschool  years swimming in a pool in the spring / summer / fall in San Jose, which is typically a bit cooler than So. Cal at that time of year.

During summer breaks,  If i wasn't in a pool, i was at the beach, even on days the fog never fully cleared the area during the afternoon.. or came in and would quickly drop the air temp from a comfortable 70- something, to the mid- 50s. 8 x's out of 10, It was only "cold" until you got used to it.  That said, yeah, lol.. if you don't slowly ease into it, it can be quite a shock.

On the other hand, As much as i prefer warmer water, theres a threshold where pool or ocean water temps are so warm, a dip isn't as refershing as it could be, esp. during a hot summer night.

[GottmitAlex]

The pacific ocean, even along Baja is usually cold. However, at that same latitude if one goes to the sea of Cortez, it's very warm. Heck, whales migrate from Alaska to the northern part of the sea of Cortez to give birth to their offspring.

 

Edited July 29, 2019 by GottmitAlex

[tropicbreeze]

It's all to do with ocean currents. In the northern hemisphere the coriolis effect sends fluids in a clockwise rotation. So with the north Pacific you get the California current moving generally southward down the western US coast from the Arctic bringing a mass of cold water. As it moves further down it starts to swing towards the west and along the equator it moves westward.

On the east US coast the coriolis effect moves equatorial water clockwise towards the north, ie. the Gulf Stream. So in the west you're always going to have the moderating effect of cold ocean waters nearer the coast, unless you can reverse the flow of the ocean currents.

[Silas_Sancona]

13 hours ago, tropicbreeze said:

It's all to do with ocean currents. In the northern hemisphere the coriolis effect sends fluids in a clockwise rotation. So with the north Pacific you get the California current moving generally southward down the western US coast from the Arctic bringing a mass of cold water. As it moves further down it starts to swing towards the west and along the equator it moves westward.

On the east US coast the coriolis effect moves equatorial water clockwise towards the north, ie. the Gulf Stream. So in the west you're always going to have the moderating effect of cold ocean waters nearer the coast, unless you can reverse the flow of the ocean currents.

Yes and no.. direction in which the CA current moves along the coast is only part of the story, Helps set up the right conditions if you will. Wind direction plays a bigger part. When it blows onshore, or from the northwest, it moves any warmer surface water offshore and draws up much cooler / colder water from below, which helps to further cool air flowing over it. 

Winds blowing from the south / south east tend to draw warmer water north from a eastward moving counter current further south that sends milder water toward southern CA. and Baja from time to time. Air comming from that direction tends to be milder / more humid at times / of more tropical origin as it flows over the area.

 Very little / no wind and, since theres no mixing of surface waters / replacing them w/ cooler water from below, surface water temps rise, sometimes quite a bit under certain conditions ( think this time last year ), reducing the marine effect / temp. contrast between coastal and more inland spots in S. Cal.  and / or N. Cal.  Once you get east of the mountains and into the deserts, a whole  new set of conditions come into play as far as temps. are concerned. Somewhat similar set up between San Fancisco and the Central Valley but a much broader gap for air to move through up there. 

Amazing how quickly weather conditions can change when traveling through the Banning Pass between Beaumont and Palm Springs, or vice versa. Have driven from 109f hot in the middle of a desert downpour coming out of Palm Springs, to coolish, breezy w/ some low clouds trying to reform overhead while looking back at the storm i just drove through sitting over the pass 10 miles or so in my rear view miror just west of Beaumont when traveling that route.  If you look at the pass itself on Google Earth, maps, whtevr. you'll see I-10 doesn't go up and over a mountain, its reletively flat through the pass.. yet the weather on either side of it can be quite different.

On a side note, some current research being done is suggesting the CA current may be slowing down, which might mean less fog / marine layer / influence, and ultimately warmer SSTs along CA, So. Cal. especially. Some are seeing signs of this ocuring already in what sp of fish, birds, other sea dwelling critters are expanding their ranges north from Baja. Sea of Cortez ( Gulf of CA. ) is also seeing similar water temp / expanding animal range trends. 

Edited July 29, 2019 by Silas_Sancona
Edit

[tropicbreeze]

Inland is always going to be a mix due to topography. That affects wind movement and also allows cold air sinks to pool colder air in certain areas. It's a whole new scenario with very localised effects.

Off shore the main mass of water remains fairly cold with a gradual upward gradient towards the equator. Shallower water along the coast and water partly land locked will warm more quickly so on the very coast itself there can be quite a water temperature difference. Also, along an uneven coastline there are eddies/counter currents, that's how fluids react up against a hard edge.  Direction the coastline lies makes a difference. But the eddies are fairly insignificant on a macro scale.

There are also effects like that along the South American west coast with desert plants only gaining moisture from fogs rolling in from off shore.

I haven't heard discussion of the CA Current slowing but have of the Gulf Stream. If it slows, or stops even, it's likely to cause freezing in western Europe (presumeably only in winter). And further back along it would be colder. Logically it would be a reverse effect on the west coast US if the CA Current slows or stops. 

However, the Coriolis Effect is driven by the rotation of the Earth, and it drives the currents. I can't imagine imagine the Coriolis Effect stopping unless Earth rotation stops. In my view it's global warming edging up the temperatures rather than the ocean currents slowing. It's a complex issue.

[Panamajack]

All the answers are correct, but I'll add this: the closer you get to the coast the more mild it is and the less variation in temperature there is. I am a few blocks from the Pacific, and although I can notice a difference between July and December, it isn't as noticeable as in other parts further inland. During the summer, when some days we experience low clouds by the coast (in SoCal we call it the "marine layer"), even though it is really annoying and it blocks the sun during the day, the nights are pretty warm, ranging from the high 60s to low 70s because the marine layer acts like a blanket, trapping all the daytime heating and preventing it from escaping into the atmosphere. This doesn't happen in inland areas and thus they have cooler night (low 60s upper 50s).

Furthermore, during winter, the coast never really gets cold, just cool. I've never experienced a freeze where I live and the lowest temperature I've experienced since I've been living here has been 45 AT NIGHT, only for a few hours until the sun came up the next day and the temp rose to a nice 65 and sunny. So anything tender, tropicals and palms will do just fine by the coast. We don't get the daytime heat that inland areas get, but we get enough warmth (usually in the 70s), sun and humidity that those plants can thrive outdoors year round. It is really fascinating. 

Edited October 4, 2019 by Panamajack

[Stevetoad]

i work in Encinitas (very close to the water) and live in Santee (18 miles from the water). Its pretty neat to see how different the temps can be. I have left my shop and it was 68f and my house was 89f. Likewise ive left my house at 5am and it was 34f and my shop was 51f. These are extreme examples but its common to see at least a difference of 10f on avg. 

Another example is that I live 6 miles from Mattyb. during the winter when I hit 32f he was still in the upper 40s. 

San Diego is the land of micro-climates thats for sure.  

[TexasColdHardyPalms]

@Panamajack you are located in just about the best USDA zones in the continental US.  Great for most plants and perfect for human comfort.  I would love nothing more than to be able to wear shorts and a light jacket all year long with no fear of mosquitos.

[Josh-O]

50 minutes ago, TexasColdHardyPalms said:

@Panamajack you are located in just about the best USDA zones in the continental US.  Great for most plants and perfect for human comfort.  I would love nothing more than to be able to wear shorts and a light jacket all year long with no fear of mosquitos.

well said!