August–The Big Heat: The Oven That is Always On

Jackrabbits cool off using their long ears and a light breeze.

By Clinton S. Powell, Naturalist

In the mountains, August can be a curse or a blessing. When the sun shines, it bores a hole from head to toe. Your hatband feels too tight, you expect to see sweat coming out from your boots.

Flies, gnats and mosquitoes even appear to be sweating. Their arrival comes like a wool blanket, and life outside can be miserable. Not only hot, but buggy-hot.    

According to the National Weather Service, the average high temperature for Julian is 84. The record high was 110 in 1969. The average low was 54; the record low was 33 in 1948. These are historical recordings, and because of global warming in recent years, record-setting temperatures still can be expected.

The most important temperatures are the low readings. Hot daytime temperatures are expected, but when it doesn’t cool off at night, problems occur.

This high nighttime temperature is the prime factor in global warming. There is a concern for agricultural crops and just about every animal species, including humans. This intense heat sucks out every drop of moisture in the air and cell damage occurs on plants, and the potential for heat stroke rises with us.    

As an example: on July 21, 2003, Phoenix had a high temperature of 117. This was a record for that day, but the overnight temperature the next morning was 96. Everything — every living creature — was at risk. Demands for air conditioners were overwhelming. I don’t know what the humidity was, but I’m sure it was very low; this is when swamp coolers are the most effective and cost-effective.    

Heat affects birds in distinctive patterns. Ravens keep their bills open and spread their wings to cool off. Warblers living in willow thickets in small creeks submerge their bodies frequently.

The California Department of Fish and Game, in conjunction with conservation groups, build quail “guzzlers.” The concrete tanks are placed at ground level, and winter rains drain into them. The open end of the guzzler has rebar set vertically to keep out coyotes, cattle and anything bigger than a quail.

Waterfowl are the most fortunate birds in hot weather. They dip, dive, dunk and every portion of their body is cooled by water.    

Mammals have the hardest time keeping cool. Shade is, of course, important. Jackrabbits have a unique system to cool off. Their long ears carry blood vessels and a light breeze helps this cooling. Deer rest in deep coniferous forests.    

Fish also have trouble in hot weather. Warm water does not contain enough oxygen for sensitive species of fish, specifically trout, to survive. When the water temperature is 70 or higher, trout are stressed, and mortality occurs after an extended time of warm water.     

Bullfrogs, tree frogs, salamanders and newts burrow deep into wet mud when the water level is low. They remain there until summer rains or autumn rains occur and emerge to their normal life.     

What can we do to keep cool? Our elevation provides a prime source for air to flow downhill. Open the windows in the evening, close them up during the day. Air conditioners work quite well, but the cost of electricity is staggering.

Basically, our summers have very little humidity. This is a good reason to put in a swamp cooler. A small motor blows air through water in baffles of aspen very quietly and very efficiently.

Seldom does the nighttime temperature stay at 65 or higher. Plan to do your outdoor chores early in the morning or late evening. During the heat of the day, there isn’t much that can cool you down, especially if you work outside.    

Summer rain comes from only one direction, Baja California. Pacific storms remain to the north. In Mexico, the warm tropical rains are called chubascos. These storms can come from the Gulf of Mexico, cross the Baja peninsula and head north laden with heavy rain. They appear as cauliflower clouds tumbled into the sky, and then thunder and lightning announces and commences the rain. Chubasco rainfall drastically varies. Usually Mt. Laguna gets the most rain; it tapers off as it nears Julian and Palomar Mountain.     

There is no fragrance that can compare to a tropical storm: Jeffrey pines exude butterscotch pudding; oats, warm and mild; willows, wet and wild and, even asphalt smells good.

We pay very heavily for each drop of rain. Humidity can be cut with a knife and every pore of your skin swells and grows pungent. But it’s worth it to see, hear and feel the grandeur of a summer storm.