About Death Valley
Death Valley is one of the hottest and driest places on earth. It holds the worldwide record for highest daytime air temperature as well as for highest nighttime air temperature, both confirmed by WMO.
The highest daytime temperature of 134°F was recorded on July 10, 1913 at Furnace Creek. The nighttime record is younger. On July 12 in 2012 temperature didn’t decrease below 107°F.
Death Valley Location
Death Valley is located in California’s Mojave-Desert, east of the Sierra Nevada in the midst of the subtropical high pressure zone and thus is characterized as one of the driest and hottest climate of the world with weak winds.
The lowest point is Badwater basin with an elevation of 282 feet below sea level. It is surrounded by several high mountain ranges. Mount Whitney, with an elevation of 14,505 feet the highest summit in the Sierra Nevada, is just 84,6 miles away.
Death Valley Temperature
Mean annual temperature is 77°F. Summer temperatures often top 120°F with lows during the night in the 90s°F. In contrast winter is much more comfortable. By day, temperatures reach about 70°F but nights are getting cold with only occasional frost. The low valley is hotter than higher elevations (dropping 3 to 5°F for every thousand vertical feet).
There are two main reasons for those extreme temperatures. As usual for deserts the vegetation is sparse and this provides a strong heating of the ground. Further the location in the basin intensify this effect. The warm and light air rises but it cannot escape because of the mountains. They are too high. And so the heat builds up in the basin.
Average annual precipitation is less than 2.5 inches. The years 1929, 1953 and 1989 are the driest years with no rain at all in Death Valley. The wettest so far was 2005 with 4.73 inches.
But why is Death Valley so dry even though the Pacific Ocean is just a few hundred miles away? You’ll find the answer in the mountains in between. Death Valley lies in the rain shadow of the Sierra Nevada.
When wet air masses move from the Ocean towards Death Valley, the mountains of the Sierra Nevada are the first natural obstacle. The air is forced to rise, thereby it cools, cool air can’t hold as much moisture as warm air so moisture condensates as rain at the western part of the mountains. On the backside of the mountains the air is less wet and cannot bring much rain anymore, mostly none at all because in case of Death Valley, there isn’t just one mountain but four. So each mountain blocks the rain and creates its own rain shadow before it actually reach Death Valley.