Heat wave broke record as hottest 20-day stretch in Sacramento history. Just how hot was it?

The heat wave from June 23 through last Friday made history as the hottest 20-day period on record in Sacramento, weather officials said.

Though other years have had higher single-day temperatures, namely the record-breaking 116-degree day in September 2022, the recent 20-day stretch is the first to break 103 degrees as an average temperature. At an average of 103.8 degrees, the heat wave surpassed the previous 20-day record average of 102.5 degrees from June 30 to July 19, 1984, according to the National Weather Service.

Other notable 20-day stretches of heat occurred in 2022 with an average of 102.4 degrees, 1996 with an average of 101.6 degrees, and 2005 with an average of 101.1 degrees.

Temperatures in downtown Sacramento also broke daily heat records on July 12 and 13.

Heat waves are a natural occurrence year-to-year in Sacramento, but scientists say that extreme heat has been exacerbated in intensity and duration by climate change, including atmospheric and ocean warming.

Such heat events are caused by a weather pattern that involves high atmospheric pressure in the Great Plains and low pressure off California’s coast, which together bring warm, moist air up from southern waters such as those in Baja California.

Notably, the weather service said Redding heat also surpassed many previous years with a stunning 107.6-degree average temperature this year over the same 20-day stretch, making it the second hottest period in history. The current record still stands at 108.1 degrees in 1978. However, Redding did record the hottest single day in history this year with a 119-degree high on July 13.