San Francisco hit 90 degrees on Friday for the first time ever in March, capping a week of record-shattering heat that stretched from California all the way to the Great Plains. The episode also produced the hottest March temperature ever recorded anywhere in the U.S.

In San Francisco, the downtown weather station, located on Mint Hill near Duboce Park, hit 90 degrees just before 4 p.m., smashing the previous all-time March record of 87 degrees set in March 2005. It is also the city’s earliest 90-degree reading on record, arriving more than two weeks before the previous mark.

San Francisco wasn’t the only place making history on Friday. 

Oakland also set a new March temperature record at 91 degrees, while also shattering the daily temperature record of 78 degrees from 2001 by a margin of 13 degrees. SFO Airport reached 89 degrees, a new all-time March record for the airport. Both Redwood City at 93 degrees and San Rafael at 89 degrees tied their March temperature records.

Santa Rosa, Napa, Richmond and San Jose also set new daily temperature records.  Temperatures around the Bay Area were running 20 to 30 degrees above normal.

Nearly 200 daily temperature records were broken or tied across 19 different states on Friday alone, with over 90 of those records occurring in California.

Dos Palmas, located near the Salton Sea in Riverside County, hit 111 degrees on Friday, setting a new March record for the state. New March temperature records were set in Sacramento, Redding, Palm Springs and Escondido.

The most extreme temperatures on Friday were occurring roughly 500 miles to the southeast, in the scorched corridor where California and Arizona converge.

Four separate weather spotter reports placed temperatures at 112 degrees in Arizona and southeastern California on Friday afternoon. If confirmed by the National Weather Service, those readings would be the highest March temperatures ever recorded in the United States. It would also fall just 1 degree short of the national April temperature record of 113 degrees set in Death Valley in 1946 and 2012. 

Friday was the final day of the unprecedented multi-day heat wave. A cooldown is expected over the weekend as the ridge of high pressure responsible for the heat flattens and the marine layer works itself back into the city. San Francisco’s forecast high of 73 degrees on Saturday is nearly 20 degrees cooler than Friday’s high.

Temperatures across the region will be in the 70s and 80s on Saturday, before a further cooldown on Sunday with much of the region seeing temperatures in the 60s.Â