A monster heat wave is gripping much of the southwestern U.S., part of a several day stretch of heat, much of it record-breaking, including Burbank reaching 112 and Anaheim hitting 106. Both of those were all-time records for the month of August there.
Seattle and Portland broke records earlier in the week. Excessive heat warnings abound from Los Angeles to San Diego to and throughout California’s Central Valley right through the holiday weekend.
One particular place to watch will be Death Valley, where the temperature could top out above 120 degrees Friday, Saturday, Sunday and Monday. More specifically, there are two threshold values to watch: 125 degrees and 126 degrees.
The 125 record is the all-time high temperature in Death Valley for the month of September (set in 2020). Reaching 126 degrees would equal the hottest temperature recorded on Earth in September. The 126-degree reading is likely a long shot but 125 might be doable.
Death Valley is notorious for heat, holding the hottest reliable temperature ever recorded on Earth at 134 degrees, set July 10, 1913 at Furnace Creek. It’s worth noting the reliable in that sentence. A temperature thought to have beaten the Death Valley record in Libya was decertified in 2012 when evidence surfaced that it was an erroneous reading.
The ‘temperature scandal’ has shed new light and questions on the Death Valley reading since it has stood for more than a century, and based on statistical analysis it should be virtually impossible to get that hot in Death Valley, even in a warming world presently.
Why does Death Valley get so much hotter than other places?
The deciding factor is geography and geology. The valley is long, surrounded by a wall of mountains that trap heat. The valley also, very importantly, is 282 feet below sea level. That means it’s the lowest place around. When a big high pressure ridge (or heat dome) sits over the valley, the air heats even more through compression. That’s because air within a high pressure dome/ridge sinks and compresses.
The median hottest September temperature since 2000 is 118 degrees, which is 2 degrees warmer than the median hottest September temps there between 1911 and 1933.
It’s only 2 degrees, but it’s enough to double the chances of hitting that 125 September record. Once again, small changes in the averages have big (exponential) impacts on the extremes.
Death Valley, like much of the rest of the world, has seen an increase in its temperature. In fact, the average annual temperature has increased an entire standard deviation over the past century.
It's only a matter of time before Death Valley hits 125. It’s been made considerably more likely thanks to climate change. Unlike in Minnesota, where an increase in temperature stresses species and ecosystems gradually, one has to wonder about a place that’s pretty inhospitable already. The few precious plants and animals that have evolved to live in Death Valley may only be able to handle so much extreme heat since they’re on the edge of existence.
How long until a place like Death Valley truly is the valley of death?
BMTN Note: Weather events in isolation can't always be pinned on climate change, but the broader trend of increasingly severe weather and record-breaking extremes seen in Minnesota and across the globe can be attributed directly to the rapidly warming climate caused by human activity. The IPCC has warned that Earth is "firmly on track toward an unlivable world," and says greenhouse gas emissions must be halved by 2030 in order to limit warming to 1.5C, which would prevent the most catastrophic effects on humankind. You can read more here.