For 4 days straight this week, Tuesday-Friday July 24-27, Death Valley, California reached a temperature of 127 degrees Fahrenheit. This sets the new record high temperature on Wednesday, with Tuesday and Thursday tieing the record for the dates.
This temperature was also likely one of the warmest temperature measured on Earth that day.
Death Valley already has the record for highest temperature ever measured on Earth at 134 degrees Fahrenheit, which occurred on July 10, 1913.
So why does Death Valley get so hot?
There are several factors involved, the most important being elevation.
The valley, at it’s base, is 282 feet below sea level. Typically, the lower the elevation, the higher the surface air pressure, and the higher the temperatures. Said in another way, with higher pressure, there are more air molecules bumping into each other and the ground, allowing for more heat to transfer between the ground and the air just above it. That leads to higher air temperatures. You can also think about mountains to understand this concept. Typically, the higher the elevation, the lower the air pressure, and the cooler it gets.
Another factor is that Death Valley is a desert. This means that it is an extremely dry with very little moisture, clouds and vegetation. This allows the sun to warm the ground and air temperature above, producing the highest possible temperature. In a more moist environment, some of the sun’s energy would be used to evaporate moisture, which has a cooling effect (known as evaporational cooling).
Deserts are formed by persistent sinking air on a larger global scale and as air sinks in the atmosphere, it warms and dries out, allowing for more extremes with temperatures. Death valley is even drier because of the Sierra Nevadas filter moisture out of the air as weather systems travel west to east across the mountains, leading to more sinking, drying and warmer air to the east, helping to add to the extremely high temperatures measure there in the summer.
In addition, Death Valley is located in very narrow, limiting air flow in the valley, allowing for air stagnation and hot air to build in the valley.
All of these factors allow temperatures to soar in Death Valley, especially during the summer times.
For WeatherNation, Meteorologist Marcus Walter.