California Statewide Heat Wave September 2017
"The greatest statewide heat wave ever recorded in California"[1] began in late August and lasted through early September, as a major high pressure system stalled over the western United States. Many locations broke daily, monthly, and all time temperature records.[2] Most notably, San Francisco broke its all time heat record, reaching 106°F on September 1.[3]
Record breaking heat waves are a classic signal of climate change. The trend in global warming has contributed to the severity and probability of 82 percent of record-hot days globally over the 1961-2010 period.[4]
The heat wave bears several signatures of heat waves on a warming planet: record-breaking heat, hot nights, high humidity, long duration, and increasing frequency.
This heat wave comes on the heels of June’s heat wave, which also broke temperatures records across the state.