Though the Los Angeles basin has been defined as hot and humid by the department of energy, it suffers from microclimates – and this has repercussions for any ill-prepared HVAC user in the San Fernando Valley.

A microclimate is a local atmospheric variation in climate due to any number of natural or urban sources. This causes certain climatic variations that cannot be easily met with standard HVAC setups that have proved viable for the remainder of the Los Angeles basin. A primary example is our San Fernando Valley, which, though part of the Los Angeles basin, will experience extremely dry weather during the summer.

Following the Weather Patterns

The San Fernando Valley owes its existence to the many jagged mountains and hills surrounding it. These natural edifices have created a unique microclimate for the valley.
The Santa Susana, San Gabriel, Verdugo, and Santa Monica mountain ranges and the Simi hills prevent most of the inland and costal winds, or warmer climates, from reaching the valley. Hence, San Fernando experiences minor fog thanks to Santa Monica, but it offers insufficient drizzle and hence fails to moisten the dry air. As a result, extremely dry summer are the norm. Residents are advised to start test running their air conditioners, change their filters, clean the air ducts, schedule maintenance and tune-ups — because most of the rain has already fallen, and the “devil winds” will soon be on their way.

Most of the Rain Has Already Fallen

The mountains have already received most of the rainfall they see each year — between November and March. As a result, the air is going to be much dryer and hotter. This means that your air conditioner will not only have to cool the air down, but it will also need to add moisture/humidity to the air. Adding a humidifier will solve the problem, but don’t forget to get the air ducts cleaned – if they have a buildup of particulate matter, moisture can turn them into a breeding ground for mold.

There is a South Wind Coming

The “Devil Santa Ana” winds will be here — igniting thermostats to as high as 108 F and cooking your AC; that’s why it is really important to keep up with your seasonal maintenance and tune ups. The Santa Ana winds pass through the baking terrain of the Mojave and Sonoran deserts, and pack in a hefty amount of heat in a stampede of millions of agitated air molecules. These winds have been here for over 5,000 years — and they will come again. Even the well-tested and maintained air conditioners do not escape unscathed, but they usually fare well.

This article was provided by American AC Heat Plumbing. Since 1981, American Air has been providing professional air conditioning and heating service and repair. Check out their $99 tune-up special – good for your air conditioner or furnace!


James Smith

As you can tell from our humble beginnings in 1981, we began as a family-owned business and stayed a locally owned air conditioning and heating company in Los Angeles county for nearly 40 years.