This is an all-time anywhere instrumental record:
More locally, the San Francisco bay area had its wettest summer day ever, and the summer in Texas is shaping up pretty nasty. Though the all-time state high temperature of 120 F still seems to be secure, an astonishing temperature of 117 F was recorded at Childress in northern Texas. As readers here will be aware, drought centered in Texas is affecting all neighboring states in both the US and Mexico as well as other parts of both countries.
At Khasab Airport in the desert nation of Oman, a remarkable record was set yesterday–the low temperature for the day was a scorching 41.7°C (107°F). The record was brought to [Jeff Masters’] attention by weather records researcher Maximiliano Herrera. The previous highest minimum temperature for the world he was able to find was set just last year at Khasab Airport, 41.2°C (106°F). The U.S. record high minimum temperature may be a 39.4°C (103°F) taken in Death Valley, California in 1970. Higher record high minimums were set there in the early 1920s, but the quality of the data is suspect. Mr. Herrera notes that Khasab Airport in Oman lies at the base of a mountain range, behind which is desert. Winds blowing from the desert towards Khasab Airport flow downhill, undergoing compression and warming, like the Santa Ana winds in California. Incredibly hot conditions in Oman in late June are common, due to a seasonal shift in winds caused by the onset of the Southwest monsoon in India.
Parts of Mexico expect respite from the drought in the form of severe floods, as a consequence of the season’s first Atlantic basin tropical storm, Arlene.