evidence: In the 2010s, 96% of 247 locations set more heat records than cold records. A century prior, during the 1910s, 54% of locations set more heat records than cold records. [...] In a stable climate, extreme highs and lows would each account for about half of all records. But since the late 1970s, daily heat records have become increasingly more common than daily cold records across the U.S.—a trend that is projected to increase with additional warming. The observed local trends toward more record heat than cold is a hallmark of climate change as the global average temperature increases. At a national scale, daily heat records have become at least twice as frequent as daily cold records. According to NOAA, in 2022 so far (through December 13), the U.S. has experienced about twice as many daily heat records than cold records.