Death Valley Gets Record for Hottest Day ... 99 Years Later Libya's claim thrown out because of unreliable thermometer By Liam Carnahan, Newser Staff Posted Sep 13, 2012 5:08 PM CDT 10 comments Comments California's Death Valley had the hottest day on record, back in 1913. (AP Photo/Google) (Newser) – California's Death Valley now has the honor of posting the hottest temperature on record, but don't blame climate change—the record-breaker of 134 degrees happened on June 10, 1913. The reason for the belated title? Libya had claimed the hottest day on record since 1992 with a thermometer reading of 136.4 degrees, but a forensics investigation has found that claim to be false, reports NBC News. A panel of World Meteorological Organization experts says the reading was taken with what was essentially a household thermometer, and the observer who recorded it was "inexperienced."