Key concepts
- A new interactive tool from Climate Central can generate daily-updating graphics to visualize temperature records for 247 U.S. cities.
- Most local U.S. observations align with the global trend: more daily heat records and fewer daily cold records. This growing gap between historic heat and historic cold over the past 50 years is an indicator of climate change.
- Climate Central analyzed the increasing frequency of record-high temperatures compared to record-low temperatures in these cities through November 2024.
Climate Central created a new interactive tool that allows users to explore record high and low temperatures for 247 U.S. cities.
- Generate a local graphic on the Graphics Dashboard
- See a map of daily records set since 2020 in the Map Explorer
- Explore data in the Data Viewer
This tool updates daily, ensuring graphics and data are accurate as records continue to be broken.
Explore daily updates for record high and low temperatures.
Local temperature extremes
To show how long-term global warming has affected local temperature extremes, Climate Central analyzed daily temperature records for each calendar day over the entire period of record at 247 U.S. locations (see Methodology). Local graphics show the percentage of hot and cold records set each decade, and from 2020-2024 (through November 26).
Most local observations follow the global trend, with daily heat records outnumbering daily cold records in recent years. Here are some highlights:
- In the 2020s, 88% (217 of 247) locations set more heat records than cold records. From January 2020 through November 26, 2024, 217 of 247 locations had more record heat than record cold.
- Over the same period (2020-2024), 21 locations across the U.S. only set records for heat (none for cold). Tampa had the most (setting 114 heat records and no cold records) - followed by Phoenix (110 heat records), Miami (102 heat records), San Juan (84 heat records), and Reno (68 heat records).
- Heat records aren't all about summer. As every season warms, unusually hot temperature records are being set year-round, including during colder months.
The Great Plains Dust Bowl drought of the 1930s marked a period of extraordinary heat extremes in the U.S. During the 1930's, warm season (May-August) daily heat records outpaced daily cold records at rates not seen again until the 2010s. Data so far for the 2020s indicate that rates of record-setting heat in the current decade may exceed those seen during the 1930s.
Changing climate, changing extremes
Record-setting temperatures are part of expected variation in daily weather. But as the planet warms overall, heat extremes are expected to become more frequent and more intense.
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 2024 so far (through November), the U.S. has experienced about three times more daily heat records than cold records.