1991-2020 Climate Normals Now Available (Updated May 11)

The National Centers for Environmental Information (NCEI) have released the new climate normals for the period 1991-2020. This information is reflected in our climate products and web pages. More information about these normals is available in the NCEI news story, and the actual data can be found on the NCEI normals page. Indianapolis climate normals can also be found on our local page.

Below is information on how the 1991-2020 values compare with the previously used 1981-2010 normals. Links to individual station's changes are included in the appropriate section. Please note that Terre Haute data is still under review and is not available at this time.

What Has Changed Locally with the New 1991-2020 Normals?

Indianapolis Area (IND)

Temperature:

All months except November experienced increases in average temperature
Greatest increase in December: +1.7°
All other months saw increases of 0.2° to 0.9°
Increases in maximum and minimum temperatures were largely uniform, but there were several months where the minimum temp increases were greater
3 months with largest average temperature increases (December, May and September) experienced the greatest rises in minimum temperatures
Seasonal average temperatures increased in all seasons (0.4° to 0.9°)
Greatest increase in winter season (DJF)
Annually, the average temperature rose 0.5°
The annual average number of days with high temperatures 90° or above increased by 5 (info added May 11)
The annual average number of days with high temperatures 32° or below increased by 1 (info added May 11)

Precipitation and Snowfall:

January, April, and June experienced the greatest increases in precipitation amounts around 0.50" to 0.70”
Largest drops in monthly precipitation occurred in May, November and December (0.25” to 0.5”)
Precipitation increased in winter (DJF), spring (MAM) and summer (JJA); decreased slightly in fall (SON)
Greatest seasonal increase during the summer (+0.64”)
Annual precipitation has increased 1.19”
Snow averages have decreased substantially in October with minor drops in February and December; these trends are largely responsible for the annual snowfall average lowering 0.4" from 25.9” to 25.5”
Subtle increases in snowfall average for January and March
Seasonal decreases of 0.8" in winter and 0.2" in fall; increase of 0.6" in spring.
The annual average number of days with 0.01" of precipitation or more decreased by 1 (info added May 11)
The annual average number of days with 0.50" of precipitation or more increased by 1 (info added May 11)
The annual average number of days with 0.1" of snowfall or more decreased by 1 (info added May 11)

Indianapolis Changes Document

Other Central Indiana Climate Sites

Temperature:

Lafayette (LAF) is the only site with a drop in annual average temperature of -0.8°
Biggest rises in annual average temperature at Shelbyville (GEZ) and Muncie (MIE) (1.5 to 1.9°). This may have to do with a smaller period of record
All other stations saw a rise of 0.4° to 0.7° annually
Largest rises occurred in the winter season (DJF) ranging from 1° to 2.6°
Minimum temperature rises were generally greater and more influential to the average temperature

Precipitation:

Annual precipitation changes were variable: Indianapolis, Lafayette, and Muncie rose while all other stations decreased
Summer season was either the same or wetter for all sites but Terre Haute and Shelbyville

Climate Stations Changes Documents