>The Greatest temperature spread I could find from warmest high to coolest high….

Firstly, try Death Valley as the “WARMEST” 128F Degrees (53C)

Then look on the coast and I found a “High” of 58F (14C)

This contrast of some 70 degrees must be literally the greatest temperature spread in such short distance anywhere on the planet. Heck it’s within one state for goodness sakes…

Why so warm and so cool?

It’s amazing at how latitude and geography creates climatic wonders and California is one of those places that shines extremes in every department, whether it be the huge cities and population, largest trees, highest mountain, lowest point in the Western Hemisphere, hottest temperature in California, the United States, North America and indeed the SECOND hottest temperature ever recorded in the world it is a place I have always marvalled at and luckily had the good fortune of visiting on three occations.

The state is home to a vast variety of weather, whether you enjoy the tranquil beach, listening the the huge rollers come in off the vast Pacific and feel the cooling breeze and moderated 70-degree sunshine, or perhaps the high mountain valleys of the Sierra, breathe in clear unpolluted alpine air or you may even want to go up to the far Northern coast where fog is thick, and moisture dripping off the huge and towering redwoods in the chilly 55-degree air where visibility is reduced to just 20 feet.

Or head 100 miles inland from the coast, in through the arid canyons and coastal ranges and feel the intense desert sun under brillient blue sky and little rain year round…

Each and every summer California will experience at least 1 or 2 heat waves, that is when the semi permanent “Four Corners High” builds and intensifies which happens every year. When pressures rise, so too do temperatures across the deserts and depending on position and where the highest pressures are, depends on where will feel the heat greatest across the state.

Two high pressure systems control California’s summertime atmosphere. Both the high sitting over the southeast California desert and the Pacific High which usually sits offshore work hand in hand and helped along by the complex geography allows vast and stunning temperature differences from coast to desert.

Here are some example from just yesterday!

Downtown Los Angeles (87F) to Pasadena (98F) in just 11.2 miles. (11 degree diff)
Morro Bay (58F) to San Luis Obispo (85F) in just 14 miles (27 degree diff)

This I believe takes the cake: Morro Bay (58F) to Paso Robles (109F) in just 37 miles (51 degree diff)

The reason for the LA to Pasadena difference in wind direction off the ocean and the protection Pasadena has from the Hollywood Hills..

Even Santa Monia which topped 75 degrees yesterday and though cooled by the marine influence, it is slightly protected and tucked by the Santa Moniica Mountains.

Oxnard which though protected you would think by the curvature of the coastal Mountains around the Santa Barbara Channel, there’s an opening between the Santa Yenz (coastal) and loftier and a little inland San Rafael Mountains, meaning the prevailing northwest wind blows straight down the slight valley and into Oxnard.

The northwest, southeast sloping coastline of California and paralleling Coast Range is crucial in the micro climates. Morning cloud, fog give way to increasing breezes as fog and cloud lift along the coast, the winds blowing off the upwelling coastal waters of the Pacific air condition the coast and put a limiter on how hot it gets (when high’s are well inland and out at sea). Coastal inlets and mountain gaps get very windy, sometimes to gale-force when we see strong inland heating as strong high pressure rules over the desert, as the temperatures crack 100, winds blow harder off the Pacific simply because heating of the land forces lowering of air pressure, rising hot air that bakes the arid desert and sunparched and tinder-dry scrubery and brush of the coastal grasses of California’s landscape has to be replaced and this is replaces by incoming cooler air off the ocean, creating all things equal and balancing things out.

summary:

high pressure offshore produces clockwise winds down the California coast, heavy, thick fogs form overnight and this marine air rushes inland through land and mountain gaps. As the sun rises and heats the land, this marine cloud and fog, pulls back to the beaches and winds start to pick up as the land heats, pressures lower as temps hit 100, that air rises off the surface, but needs to be replaced, replaced, it is, by the clockwise wind flow from the Pacific high.

Places such as Paso Robles, just in behind the coast range on the inland side does not recieve cooling moderation off the Pacific as the mountains are too high for the cloud, fog or wind to get inland, therefore even though 10-14 miles away from the Pacific, skies are clear and a blowtorch sun heats the community to a sweltering 109 degrees. The coast ranges up ad down the California coast acts like a wall seperating 50 degrees between the coast and inland areas.

A great display of temperature progression can be found in a 123 mile stretch from Santa Monica to Palm Springs. Going from a comfortable Mediterrannean climate to harsh, arid desert climate. At night when things cool off it’s surprising how far inland clouds and fog can reach, but between Santa Monica and Palm Springs there are several mountain ranges and they rise higher as one goes inland. Pacific air is nonexistent in the low desert of the Coachella Valley as many mountain ranges block off Pacific air completely. It is evident as you drive inland there are rapid rises in temperature as you move away from the ocean, you literally only have to drive a few miles around or over mountains to have a striking difference in the overall weather. Maliby and Canoga Park in the San Fernando valley is 10 miles apart yet I’ve seen a difference between 70 degrees and 112 degrees! Woodland Hills in the San Fernand valley, tucked in on three sides by mountains allowed that community in 2006 during an extraordinary heat wave to hit a blowtorch 119 degrees whilst a mere 14 miles on the coast it was barely making 80.

Here are more examples from yesterday.

Coast: Half Moon Bay 63 degrees, Eureka 62 degrees, Monterey 66 degrees, Crescent City 60 degrees.

LA Basin, unprotected from marine influence: LAX 75 degrees and 12 miles inland Downtown LA 87 degrees. 11 miles further inland, Pasadena 98, in the San Fernando Valley, tucked in round the lofty Santa Monica Mountains it was over 100 degrees.

San Gabriel Valley between inland LA and San Gabriel Mountains: Ontario 102 degrees, San Bernardino 108 degrees

Behind the 10-12,000 foot wall of the San Gabriel Mountains is the high desert, northeast of the LA basin: Lancaster 111 degrees, Palmdale 110.

East of LA and over the San Bernardino Mountains into the Apple Valley and western edge of ther Mojave Desert (high desert, 2,000-3,500ft: Twentynine Palms 112 degrees, Barstow 114 degrees. The elevation does play a role in trimming back the still brutal heat but Baker which lies in a lower valley in the overall high desert region and broiled in July 2007 to an unbearable 125 degrees!!

Southeast of LA, into the cannyon region: Yorba Linda usually upper 80s to low 90s when LA basin is only mid-70s, but influenced by marine cloud and fog and does recieve winds off ocean.

In behind the Santa Ana Mountains: Riverside in the Inland Empire 105 degrees.

The San Jacinto Range lie between the Inland Empire and Coachella Valley which drops closer to sea level and is considered the low desert or Colorado desert: Palm Springs 118 degrees, continue along I-10 and you drop below sea level where the Salton Sea lies, temps of 125-130 can be achieved here during the worst heat events.

Go northeast of LA towards the southern Sierra Nevada, climb up and over countless mountain ranges, into the high desert and drop over 14,000ft mountain and into Death Valley, 282 feet BELOW sea level, home to yesterday’s 128 degrees and regularly 100 degree lows when conditions are right……

Thanks for reading. More on Death Valley heat and why, coming up soon.

-Mark