New 1981-2010 Climate Normals Began on August 1st (Monthly Climate Normals Added)

The National Climatic Data Center (NCDC) is responsible for producing 30 year climate normals of numerous climatological variables every 10 years for U.S. locations. The primary variables include temperature, precipitation, and derived products such as heating and cooling degree days. Normals serve as a baseline average of important climate variables that are used to understand average climate conditions at any location and serve as a consistent point of reference.

In this latest set of normals (1980-2010), the 1971-1980 decade was removed (generally considered a cool decade) and the 2000-2010 decade was added (warmer by comparison). As a result, the 1980-2010 average temperature across the United States is now approximately 0.5 F degrees warmer than the 1971-2000 period. However, this warming is not uniform across the country or from season to season. For instance, the 1981-2010 average high temperature for the mid section of the U.S. is cooler in July compared to the previous set of normals. Meanwhile, the January normal lows are much warmer across the Northern Plains and Upper Mississippi River Valley compared to 1971-2000. The graphics below illustrate the changes, along with the overall warming by state from the old set of normals to the new set.

change in normals
change in normals by state

Below is a comparison of how the 1971-2000 (Old) normals compare to the 1981-2010 (New) normals for La Crosse, WI and Rochester, MN.

Old is the 1971-2000 normals. New is the 1981-2010 normals. Red text indicated a warmer temperature compared to the old set of normals. Blue text indicates cooler temperatures compared to the previous normals. Green text indicated more precipitation, while Brown text indicates less.

La Crosse Jan Feb Mar Apr May Jun
  Old New Old New Old New Old New Old New Old New
High Temp 25.5
25.9
 32.4
31.4
 44.6
43.9
 59.7
59.3
 72.5
70.7
 81.3
80.0
Low Temp 6.3 8.9 12.8 13.6 24.5 25.2 37.1 37.9 48.7 48.7 57.9 58.5
Ave Temp 15.9 17.4 22.6 22.5 34.6 34.5 48.4 48.6 60.6 59.7 69.6 69.2
Precipitation 1.19" 1.12" 0.99" 1.05" 2.00" 2.04" 3.38" 3.34" 3.38" 3.52" 4.00" 4.34"
Snowfall 12.9" 10.7" 8.0" 8.2" 7.2" 7.1" 2.0" 1.7" T 0 0 0
  Jul Aug Sep Oct Nov Dec Year
  Old New Old New Old New Old New Old New Old New Old New
High Temp 85.2
84.1
 82.5
81.5
 73.7
73.2
 61.1
59.9
 43.6
43.8
 29.9
29.1
 57.7
57.0
Low Temp 62.8 63.2 60.7 61.3 51.7 52.4 40.1 40.4 27.4 28.1 13.6 14.2 37.0 37.8
Ave Temp 74.0 73.7 71.6 71.4 62.7 62.8 50.6 50.2 35.5 35.9 21.8 21.6 47.3 47.4
Precipitation 4.25" 4.26" 4.28" 4.29" 3.40" 3.56" 2.16" 2.17" 2.10" 2.01" 1.23" 1.36" 32.36" 33.06"
Snowfall 0 0 0 0 T 0 0.2" 0.2" 4.4" 4.1" 9.6" 11.3" 44.3" 43.3"

 

Rochester Jan Feb Mar Apr May Jun
  Old New Old New Old New Old New Old New Old New
High Temp 19.9
23.6
 26.2
28.1
 38.7
40.5
 54.8
57.0
 67.7
68.7
 76.6
78.0
Low Temp 3.7 7.7 10.6 12.4 22.6 24.3 34.6 36.4 46.1 47.4 55.6 57.2
Ave Temp 11.8 15.7 18.4 20.3 30.6 32.4 44.7 46.7 56.9 58.1 66.1 67.6
Precipitation 0.94 0.86" 0.75" 0.83" 1.88" 1.88" 3.01" 3.24" 3.53" 3.63" 4.00" 4.68"
Snowfall 11.9" 12.0" 7.8" 8.5" 9.0" 8.7" 4.3" 3.3" T T 0 0
  Jul Aug Sep Oct Nov Dec Year
  Old New Old New Old New Old New Old New Old New Old New
High Temp 80.1
81.4
 77.5
78.9
 69.2
71.4
 56.9
58.4
 38.7
41.6
 24.5
27.1
 52.6
54.7
Low Temp 60.1 61.3 58.0 59.3 48.7 50.4 37.1 38.4 23.7 26.0 10.1 12.2 34.2 36.2
Ave Temp 70.1 71.4 67.7 69.1 58.9 60.9 47.0 48.4 31.2 33.8 17.3 19.7 43.4 45.4
Precipitation 4.61" 4.55" 4.33" 4.52" 3.12" 3.45" 2.20" 2.24" 2.01" 1.91" 1.02" 1.23" 31.40" 33.02"
Snowfall 0 0 0 0 T 0 1.0" 0.8" 7.1" 6.1" 11.6" 12.5" 52.7" 51.9"

More details on the new climate normals will be added to this, or other news stories, over the next few weeks. In the meantime, consult the links below for more information, or take a look at some of the new normals. Note that the normal files are not "user friendly" and its suggested that you peruse the "Read Me" text file for help in interpreting them. A more friendly interface of accessing the normals will be made available in the near future.

The National Weather Service will use these normals starting August 1st.

1981-2010 Normals

Again, please note these files are not easy to interpret. They are provided here as a service to our more technical or inquisitive users. Please consult the "Read Me" text file for information on how to read these files.

Monthly Climate Normals for Other Locations:

 



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