On Thursday morning, July 12, 2012 the low temperature at Death Valley, California dropped to just 107°F (41.7°C), after hitting a high of 128° (53.3°C) the previous day. Not only does the morning low temperature tie a record for the world’s warmest low temperature ever recorded, the average temperature of 117.5°F is the world’s warmest 24-hour temperature on record. According to weather records researcher Maximiliano Herrera, the only other place in the world to record a 107°F low temperature was Khasab Airport in the desert nation of Oman on June 27, 2012. The previous U.S. record high minimum temperature may be a 103°F (39.4°C) observed in Death Valley, California in 1970. Higher record high minimums were set there in the early 20th Century, but the quality of the data is suspect.

Figure 1. Badwater, Death Valley, California. Wide open spaces, infinite views. What’s not to love about this place? Image credit: Wunderphotographer SonomaCountyRAF.

Wednesday’s high of 128°F (53.3°C) was the 10th hottest temperature in U.S. history, and the hottest temperature measured in the U.S. since July 18, 2009, when Death Valley recorded another 128° reading. The only hotter temperatures in U.S. history were all measured at Death Valley, the most recent one being the 129° measured on July 6, 2007. The all-time high for Death Valley is the 134° reading of July 10, 1913.

Temperatures have cooled considerably at Death Valley over the weekend, and the forecast for Monday calls for for a downright chilly high of just 110°. That’s sure to be a disappointment for the ultramarathoners in the grueling Badwater Ultramarathon, which begins Monday in Death Valley. Covering 135 miles (217km) non-stop from Death Valley to Mt. Whitney, CA, it is the most demanding and extreme running race offered anywhere on the planet. I’m sure they would have liked to have had the distinction of running their race last Thursday, during the hottest 24-hour period ever recorded on the planet!

Jeff Masters