Record High & Low Daily Temperatures in the U.S. - Graphs and Tabular Data

DayRec: United States Record-Maximum/Minimum Daily Temperatures

Dataset Tabs Default Display


Record high and low temperatures generate tremendous interest, largely because of the potential for impacts on human health, the environment, and built infrastructure. Changes in the ratio of record high and low temperatures (extremes) are also indicator of climate change.

DayRec offers three kinds of prepared charts that characterize and provide context for record temperatures*:

  • Scatter plots show the years that different types of records were set for each day of the year. 
  • Bar charts show the decadal frequency of record-setting Tmax's and Tmin's, and
  • Graphs show record Hot Tmax and Cool Tmax values for each day of the year 

Where do these data come from?

DayRec displays daily maximum temperature (Tmax) and minimum temperature (Tmin) observations from a subset of stations in the Global Historical Climatology Network (GHCN) - Daily database. Project developers started with a subset of the 1218 stations in the U.S. Historical Climatology Network (USHCN). Of these, 200 stations met their stringent requirements for very low percentages of missing data—these are categorized as Class 1 stations and marked in blue in the DayRec interface. Records from an additional 224 stations met slightly less stringent requirements—these are categorized as Class 2 stations and marked in green. Learn more about DayRec's Data and Methods page.

*NOTE: Data displayed in the DayRec system are not corrected for biases associated with changes in instrumentation, observing practices, or the local observing environment that can occur through time. Therefore, variability and trends in record high and low temperatures determined from GHCN-Daily data may be due to factors other than changes in climate. Additional information on climate data, the need for corrections to temperature data, and observed and projected changes in climate extremes are available in the references provided.  NOAA's NCEI provides other temperature data sets, such as GHCN-Monthly, which have been corrected for time-dependent biases.