San Francisco is experiencing what locals call "second summer," otherwise known as the early fall time period that is typically when the northern California city is at its hottest. "But this one is more extreme," a meteorologist tells the New York Times—so extreme that it's reaching near-record highs, and in other parts of the Bay Area, heat records are being broken. "It's very rare to be in the 90s at all in San Francisco. But in October, it's even more rare," says the meteorologist. The temperature hit 95 degrees on Tuesday—the city's hottest day of the year, per the Guardian—and an excessive heat warning is in effect through Thursday.
Though the record high for October 1 in San Francisco was 97 degrees in 1980, a record high for the date was set Tuesday just a bit south in San Jose, where it hit 100 degrees, as well as a bit to the east in Livermore, where it hit 103, CBS News reports. A number of other cities in the area recorded temperatures above 100, with officials warning of "a significant threat to property or life," including the risk of heat-related deaths or wildfires. After the excessive heat warning expires, high temperatures are still expected to linger through the weekend. (More San Francisco stories.)