Last updated October 15, 2021

California Statewide Heat Wave September 2020

United States

Climate change is exacerbating the "kiln-like" heat wave breaking records across California this early September. Long-term warming means that hot weather patterns, like the high-pressure system and weak sea breeze driving up temperatures in California, can produce unprecedented extremes. By one estimate, temperatures during rare California heat waves are about three to four degrees Fahrenheit warmer than they would have been without human interference in the climate system.

The heat wave is not an isolated incident but part of large-scale trends driven by global warming that are increasing the frequency of extreme events in California and around the world. A similar extreme and record-breaking September heat wave affected California just three years ago. The September 2017 heat wave set monthly and all-time records that are now, once again, being broken. The short-lived nature of these major temperature records is a clear signal of climate change.

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Heat Wave
Greenhouse Gas Emissions
Global Warming
Large Scale Global Circulation Change
Atmospheric Blocking Increase
Air Mass Temperature Increase
Extreme Heat and Heat Waves
California Statewide Heat Wave September 2020