on 17 june 2021, furnace creek recorded a temperature of 125°f (51°c) on-site, while nearby official observations reached 128°f. this occurred during a widespread and well-documented heatwave across the western united states.

a strong upper-level ridge was in place over the region, centered across the four corners and extending westward into california and nevada. subsidence under the ridge led to clear skies, dry air, and near-maximum solar heating. surface analysis from 21z (2 pm pdt) shows high pressure dominating the southwest with minimal cloud cover and widespread triple-digit temperatures.

this setup created ideal conditions for excessive daytime heating in death valley, a location already well below sea level and prone to extreme temperatures due to its topography and dry ground surface.