National Weather Service United States Department of Commerce

1981-2010 Climate Normals To Take Effect August 1st

Updated climate normals for the period 1981-2010 have been released by the National Climatic Data Center (NCDC). Climate normals are the latest three-decade averages of climate variables, including temperature and precipitation. The new normals replace the 1971-2000 normals.

The National Weather Service began incorporating the new 1981-2010 climate normals into our climate text products beginning on August 1, 2011.

  • This impacts the following local climate products:
  • Daily Climatological Report (CLI)
  • Monthly Climatological Report (CLM)
  • Preliminary Local Climatological Data Report (CF6)

Any product that has data that crosses the August 1st implementation date will use the new 1981-2010 climate normals for required calculations for the entire period. Products issued prior to the change date will not be reissued using the new climate normals.

Climate normals are currently calculated every 10 years by the NCDC and are based upon an average of 30 years of climate data. Additional information can by found on the NCDC website at: http://www.ncdc.noaa.gov/oa/climate/normals/usnormals.html


Jackson Normals

Average Temperature

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
'81-'10
Normals
45.7 49.5 56.9 64.1 72.3 79.0 81.6 81.3 75.6 65.1 55.7 47.8 64.6
'71-'00
Normals
45.0 49.2 56.8 63.4 71.5 78.5 81.4 80.9 75.5 64.4 54.8 47.6 64.1
Difference +0.7 +0.3 +0.1 +0.7 +0.8 +0.5 +0.2 +0.4 +0.1 +0.7 +0.9 +0.2 +0.5

High Temperature

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
'81-'10
Normals
56.1 60.5 68.5 75.9 83.1 89.5 91.6 91.6 86.7 77.2 67.4 58.2 75.6
'71-'00
Normals
55.1 60.3 68.1 75.0 82.1 88.9 91.4 91.4 86.4 76.8 66.3 57.9 75.0
Difference +1.0 +0.2 +0.4 +0.9 +1.0 +0.6 +0.2 +0.2 +0.3 +0.4 +1.1 +0.3 +0.6

Low Temperature

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
'81-'10
Normals
35.3 38.5 45.3 52.2 61.6 68.6 71.6 70.9 64.6 53.1 44.0 37.3 53.7
'71-'00
Normals
35.0 38.2 45.4 51.7 61.0 68.1 71.4 70.3 64.6 52.0 43.4 37.3 53.2
Difference +0.3 +0.3 -0.1 +0.5 +0.6 +0.5 +0.2 +0.6 0.0 +1.1 +0.6 0.0 +0.5

Precipitation

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
'81-'10
Normals
4.97" 4.76" 5.04" 4.96" 4.38" 4.12" 4.81" 4.24" 3.03" 3.92" 4.76" 5.15" 54.14"
'71-'00
Normals
5.67" 4.50" 5.74" 5.98" 4.86" 3.82" 4.69" 3.66" 3.23" 3.42" 5.04" 5.34" 55.95"
Difference -0.70" +0.26" -0.70" -1.02" -0.48" +0.30" +0.12" +0.58" -0.20" +0.50" -0.28" -0.19" -1.81"

Snowfall

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
'81-'10
Normals
0.3" 0.1" 0.1" 0.1" 0.0" 0.0" 0.0" 0.0" 0.0" 0.0" 0.0" 0.3" 0.9"
'71-'00
Normals
0.5" 0.1" 0.1" T 0.0" 0.0" 0.0" 0.0" 0.0" 0.0" T 0.2" 0.9"
Difference -0.2" 0.0" 0.0" +0.1" 0.0" 0.0" 0.0" 0.0" 0.0" 0.0" 0.0" +0.1" 0.0"

Meridian Normals

Average Temperature

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
'81-'10
Normals
44.8 48.7 55.6 62.7 70.8 77.6 80.6 80.3 74.8 64.1 54.7 47.2 63.6
'71-'00
Normals
46.1 50.2 57.3 63.8 71.7 78.5 81.7 81.4 76.1 64.8 55.7 48.9 64.7
Difference -1.3 -1.5 -1.7 -1.1 -0.9 -0.9 -1.1 -1.1 -1.3 -0.7 -1.0 -1.7 -1.1

High Temperature

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
'81-'10
Normals
56.5 61.0 69.0 76.2 83.2 89.2 91.8 91.5 86.8 77.3 67.7 58.8 75.8
'71-'00
Normals
57.5 62.6 70.3 77.1 83.9 90.1 92.9 92.9 88.0 78.3 68.5 60.5 76.9
Difference -1.0 -1.6 -1.3 -0.9 -0.7 -0.9 -1.1 -1.4 -1.2 -1.0 -0.8 -1.7 -1.1

Low Temperature

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
'81-'10
Normals
33.1 36.4 42.3 49.1 58.5 66.1 69.4 69.0 62.9 51.0 41.6 35.6 51.3
'71-'00
Normals
34.7 37.7 44.3 50.4 59.5 66.8 70.5 69.8 64.2 51.3 42.8 37.2 52.4
Difference -1.6 -1.3 -2.0 -1.3 -1.0 -0.7 -1.1 -0.8 -1.3 -0.3 -1.2 -1.6 -1.1

Precipitation

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
'81-'10
Normals
5.13" 5.60" 5.42" 4.78" 4.50" 4.40" 5.14" 3.99" 3.43" 3.76" 4.95" 5.06" 56.16"
'71-'00
Normals
5.92" 5.35" 6.93" 5.62" 4.87" 3.99" 5.45" 3.34" 3.64" 3.28" 4.95" 5.31" 58.65"
Difference -0.79" +0.25" -1.51" -0.84" -0.37" +0.41" -0.31" +0.65" -0.21" +0.48" 0.00" -0.25" -2.49"

Snowfall

  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
'81-'10
Normals
0.3" 0.0" 0.4" 0.2" 0.0" 0.0" 0.0" 0.0" 0.0" 0.0" 0.0" 0.1" 1.0"
'71-'00
Normals
0.4" T 0.2" 0.1" 0.0" 0.0" 0.0" 0.0" 0.0" 0.0" T T 0.7"
Difference -0.1" 0.0" +0.2" +0.1" 0.0" 0.0" 0.0" 0.0" 0.0" 0.0" 0.0" +0.1" +0.3"

Additional Sites/Parameters

In addition to the information above, many other daily, monthly, seasonal, and annual normals are available. 1981-2010 normals information has been released for several sites across the ArkLaMiss, including primary climate sites, airports, and NWS COOP stations. This data is currently available from NCDC in a tabular format. To help understand how to interpret these data files, please consult the readme.txt file provided by NCDC.

Sites with Complete/Nearly Complete Data - These sites have full temperature and precipitation normals, which are based on either a complete period of record, or a sufficient set of data to provide representative normals. Snowfall normals are also available for some sites.
Other sites - These sites are missing either temperature or precipitation normals, or the period of record is too short to provide representative normals (provisional normals or quasi-normals). Snowfall normals are also available for some sites.

Questions/Comments

If you have questions or comments regarding the new climate normals for the National Weather Service Jackson, MS Forecast Area, please contact:

Climate Services Focal Point
234 Weather Service Dr.
Flowood, MS 39232
Phone 601-936-2189

Or send an email to sr-jan.webmaster@noaa.gov