Mapping the Environment
Additional Data Sets

These data sets were created from information gathered from the Climate Atlas of the United States (NOAA/NCDC) and are for the lower 48 states.

Temperature Data

Mean Daily Average Temperature (2.80 MB)

Mean Daily Temperature Range (6.76 MB)

Mean Daily Maximum Temperature (3.43 MB)

Mean Daily Minimum Temperature (3.16 MB)

Record Extreme Maximum Temperature (3.00 MB)

Record Extreme Minimum Temperature (3.16 MB)

Mean Number of Days with Temperatures Greater than 90°F (3.75 MB)

Mean Number of Days with Temperatures Less than 32°F (4.86 MB)

Median/Mean Length of Freeze-Free Period (568 KB)

Last 32°F Temperature in Spring (1.08 MB)

First 32°F Temperature in Fall (911 KB)

Mean Dew Point Temperature (2.24 MB)

Precipitation Data

Mean Total Precipitation (7.49 MB)

Record Total Precipitation (9.58 MB)

Mean Maximum Daily Precipitation (4.83 MB)

Mean Number of Days with Measurable Precipitation (5.32 MB)

Mean Number of Days with Freezing Precipitation (523 KB)

Dates of First/Last Snowfall (1.56 MB)

Mean Total Snowfall (7.63 MB)

Record Total Snowfall (5.06 MB)

Mean Maximum Daily Snowfall (9.06 MB)

Mean Number of Days with Measurable Snowfall (3.26 MB)

Mean Snow Depth (5.14 MB)

Mean Number of Days with Measurable Snow Depth (3.11 MB)

Hail Events with Diameters Greater than .75 Inch (5.50 MB)

Other Climate Data

Mean Wind Speed (1.03 MB)

Mean Wind Speed and Prevailing Direction (479 KB)

Tornado Tracks (5.03 MB)

Landfalling Hurricanes 1981–2001* (165 KB)

Landfalling Hurricanes 1950–2001* (219 KB)

Major Landfalling Hurricanes 1899–2001* (191 KB)

Mean Number of Days with Heavy Fog (1.26 MB)

Mean Percentage of Visibility of Less than .25 Mile (904 KB)

Mean Percentage of Visibility of Greater than 10 Miles (1.25 MB)

Mean Relative Humidity (3.58 MB)

Mean Sunshine Percentage (749 KB)

Spring Seasonal Vegetation Cover* (331 KB)

Summer Seasonal Vegetation Cover* (316 KB)

Autumn Seasonal Vegetation Cover* (321 KB)

Winter Seasonal Vegetation Cover* (310 KB)


  1. Choose a data set.
  2. Click on the title to download a zip file containing the data files.
  3. When asked, choose "Save to Disk".
  4. Unzip the file using any file decompression program. If you don't have such a program, you can download one for free.

For more information about the data sets (including a file name key) see the text document "atlaskey.txt". A copy of this document is included in each zip file.

Files marked with an asterisk (*) contain pdf files that can be read using Adobe® Reader.

Get Adobe ReaderAdobe® Reader is free and can be acquired by clicking on the link at right.

Glossary of Terms

Dew Point – the temperature that air must reach before condensation (vapor becomes a liquid) can occur.

Mean – average of a number of different amounts.

Median – the middle value in an ordered set of values.

Precipitation – any form of water particles that fall from the clouds and reach the ground. Examples are rain, snow, sleet, and hail. Fog, dew, frost, and clouds are not forms of precipitation.

Relative Humidity – how much water the air is holding divided by how much water the air is capable of holding.

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