1981-2010 U.S. Climate Normals
The 1981–2010 Climate Normals are NCEI's latest three-decade averages of climatological variables, including temperature and precipitation. This product replaces the 1971–2000 Climate Normals product, which remains available as historical data.
Search for temperature and precipitation Climate Normals for over 9,800 stations across the United States. Select from tabs and drop-down menus to view monthly, daily, annual, seasonal, or hourly Normals by location, station, and date.
Select locations on the interactive map by station, zip code, city, county, or state for temperature and precipitation Normals as well as supplemental Normals, which include snowfall, heating and cooling degree days, frost and freeze dates, and growing degree days.
U.S. Climate Atlas
This tool allows users to view interactive maps of average monthly and annual minimum temperature, maximum temperature, and total precipitation. In addition, monthly maps of minimum temperature, maximum temperature, and precipitation from 1895 through 2015 are available. There are several tools for animating maps and comparing pairs of maps. Downloading of the images is available on the site.
Supplemental Monthly Temperature Normals
The supplemental monthly temperature normals include 4,463 stations across the United States. This special product line provides multiple estimates of monthly temperature normals using different definitions of "normal" so that users can make better-informed decisions in their planning applications. The values are presented in tabular format and available as PDF files.
Download ASCII versions of the full suite of Climate Normals products from our FTP area. This type of access is for individuals who have experience with FTP and programming languages. We recommend that you review the readme.txt file prior to downloading the data as it describes all file information and locations.
Download ASCII versions of the full suite of Climate Normals products from our HTTP area rather than the FTP area as described above.
What are Climate Normals?
Why does NOAA produce Climate Normals?
What are Climate Normals used for?
Were the 1981–2010 Climate Normals computed in the same way as previous versions?
What qualifies or disqualifies a station to be included in Climate Normals products?
How many stations are included in the Climate Normals?
What do Climate Normals tell us about global warming or climate change?
What portion of the difference from the new Climate Normals and the previous Climate Normals was due to climate change?
Compared to the previous Climate Normals, the new Climate Normals includes the decade of the 2000s and loses the decade of the 1970s. As the 2000s were warmer than the 1970s, this has had a warming influence on the Climate Normals. Comparing these decades using our best dataset for climate change analysis, the USHCN, we find that the decade of the 2000s was about 1.5°F warmer than the 1970s. For maximum, minimum, and mean temperature the difference, respectively, was 1.37°F, 1.55°F, and 1.46°F. As the Climate Normals are an average of three decades, this warmed the new Climate Normals by approximately 0.5°F. The difference between these values and the actual difference between the reported 1971–2000 Normals and the new Normals are caused by station moves, changes in observing practices or instruments, etc.
What are heating and cooling degree days? What are growing degree days?
How can I obtain heating and cooling degree day Normals set to different base temperatures? And for growing degree units?
How can I obtain Climate Normals for other weather elements such as dew point temperature, sea level pressure, and wind?
How does the transition to ASOS affect the computation of Climate Normals?
How do the 1981–2010 Climate Normals compare to Alternative Normals and Dynamic Normals?
Do other agencies and individuals compute their own Climate Normals?
Where can I find more information about the 1981–2010 Climate Normals and how they were computed?
For a broad overview of NOAA's 1981–2010 Climate Normals, see:
Arguez, A., I. Durre, S. Applequist, R. S. Vose, M. F. Squires, X. Yin, R. R. Heim, Jr., and T. W. Owen, 2012: NOAA's 1981-2010 U.S. Climate Normals: An Overview. Bulletin of the American Meteorological Society, 93, 1687-1697, doi:10.1175/BAMS-D-11-00197.1.
For a detailed description of precipitation, snowfall, and snow depth Normals, see:
Durre, I., M. F. Squires, R. S. Vose, X. Yin, A. Arguez, and S. Applequist, 2012: NOAA's 1981-2010 U.S. Climate Normals: Monthly Precipitation, Snowfall, and Snow Depth. Journal of Applied Meteorology and Climatology, 52, 2377–2395, doi:10.1175/JAMC-D-13-051.1.
Durre, I., M. F. Squires, R. S. Vose, A. Arguez, S. Applequist, and X. Yin, 2012: Computational Procedures for the 1981-2010 Normals: Precipitation, Snowfall, and Snow Depth. NCDC Report, 10 pp. PDF
Durre, I., and M. F. Squires, 2015: White Christmas? An Application of NOAA's 1981-2010 Daily Normals. Bulletin of the American Meteorological Society, 96, 1853-1858, dx.doi.org/10.1175/BAMS-D-15-00038.1.
For a detailed description of temperature Normals, see:
Arguez, A., S. Applequist, R. S. Vose, I. Durre, M. F. Squires, and X. Yin, 2012: NOAA's 1981-2010 Climate Normals: Methodology of Temperature-related Normals. NCDC Report, 7 pp. PDF
For a detailed description of Hourly Normals, see:
Applequist, S., A. Arguez, I. Durre, M. F. Squires, R. S. Vose, and X. Yin, 2012: 1981-2010 U.S. Hourly Normals. Bulletin of the American Meteorological Society, 93, 1637-1640 52, 2377–2395, doi:10.1175/JAMC-D-13-051.1.
For more information about the "Constrained Harmonic Approach" used to calculate daily temperature Normals, see:
Arguez, A., and S. Applequist, 2013: A Harmonic Approach for Calculating Daily Temperature Normals Constrained by Homogenized Monthly Temperature Normals. Journal of Atmospheric and Oceanic Technology, 30, 1259–1265, doi:10.1175/JTECH-D-12-00195.1.
For information about the frost-freeze and growing degree day Normals, see:
Arguez A., 2012: NOAA's 1981-2010 Climate Normals: Supplemental Normals. NCDC Report, 4 pp. PDF
The vast majority of the data used to calculate NOAA's 1981–2010 Climate Normals come from the Global Historical Climatology Network–Daily database. For more information on this database, see:
Menne, M., I. Durre, B. G. Gleason, T. G. Houston, and R. S. Vose, 2012: An overview of the Global Historical Climatology Network-Daily database. Journal of Atmospheric and Oceanic Technology, 29, 897-910, doi:10.1175/JTECH-D-11-00103.1.
Durre, I., M. J. Menne, B. E. Gleason, T. G. Houston, and R. S. Vose, 2010: Comprehensive automated quality assurance of daily surface observations. Journal of Applied Meteorology and Climatology, 8, 1615-1633, doi:10.1175/2010JAMC2375.1.
The 1981–2010 temperature Normals are based on monthly temperature values that have undergone robust quality control and homogenization to address changes in observing practices. For more information on these techniques, see:
Menne, M. J., and C. N. Williams, Jr., 2009: Homogenization of Temperature Series via Pairwise Comparisons. Journal of Climate, 22, 1700-1717, doi:10.1175/2010JAMC2375.1.
Menne, M. J., C. N. Williams, Jr., and R. S. Vose, 2009: The United States Historical Climatology Network Monthly Temperature Data Version 2. Bulletin of the American Meteorological Society, 90, 993-1007, doi:10.1175/2010JAMC2375.1.
Cite dataset when used as a source. See the dataset's DOI landing page for citation details at doi:10.7289/V5PN93JP.