Mojave Desert Climate Dry Tropical Climate (BW)
The Mojave Desert is found at elevations of 2,000 to 5,000 feet, and is considered a "high desert". It is a transition desert between the hot Sonoran Desert to the south, and the cold Great Basin Desert to the north. The climate of the Mojave Desert has extreme fluctuations of daily temperatures, strong seasonal winds, and clear skies.
Temperatures have been as low as 8°F in January and as high as 119°F in August. In May the temperature will begin to climb in excess of 100°F and continue into October. The night temperatures in July and August can at times be in the low to mid 90s.
In late winter and early spring the wind is a prominent feature, with dry winds blowing in the afternoon and evening. Winds in excess of 25 mph, with gusts of 75 mph or more are not uncommon. Although it is windy during all months, November, December and January are the calmest.
The humidity is below 40% most of the year. During most winter nights, and during and after summer rains the humidity can get above 50%.
The Mojave Desert lies in the rainshadow of the Coast Ranges and receives an average annual precipitation of 5 inches. Most of the rain falls between November and April. There is, however, a summer thunderstorm season from July to September with violent and heavy rainstorms possible. In 1986 only 1.5 inches of rain fell on the Eastern Mojave Desert, while in 1983 6.5 inches came down. May and June are usually the driest months.
During cycles of El Niño, as we have experienced in recent years, more rain falls on the Mojave Desert than usual. The runoff has resulted in shallow ponds in the normally dry washes and playas. For the last few years there has been more rain overall than the climate of 20 years ago.
The Mojave Desert experienced very heavy rains in the 1950s, when surface runoff resulted in severe erosion of gullies and washes and heavy silt deposits. A long dry period followed, ending with the present wet period.
According to the U.S. Geological Survey, vegetation has grown denser since the early 1970s, most likely due to the increased precipitation. They conclude that the climate of the Mojave Desert hasn't been static, and has experienced many changes this century. Their ongoing research suggests that the recent climate variation has influenced both the landscape and the plants and animals of the desert ecosystem.
A.R. Royo, "The Mojave Desert - Desert USA", http://www.desertusa.com/du_mojave.html
"Desert Climate", http://biology.fullerton.edu/facilities/dsc/zz_climate.html
"Desert Watch - Mojave", http://www.enviroweb.org/desertwatch/DW-Mojave.html
"Climate History in the Mojave Desert Region", http://www-wmc.wr.usgs.gov/mojave/climate-historymain.html