Monthly Weather Report

Iowa Monthly Weather Summary – December 2024

General Summary

Temperatures averaged 28.2 degrees or 3.2 degrees above normal, while precipitation averaged 1.24 inches or 0.13 inch below normal. December 2024 ties 1940 and 2003 as the 37th warmest in 152 years of statewide records; it ties 1881 as the 86th driest. A warmer December occurred just last year (3rd warmest) while a drier one was last recorded in 2021.

Temperatures

Monthly average temperatures were above normal statewide with the warmest conditions reported across the middle of the state. December’s statewide average maximum temperature was 36.0 degrees, 2.8 degrees above normal while the average minimum temperature was 20.4 degrees, 3.6 degrees below normal. Several stations reported the month’s high temperature of 65 degrees on the 7th, on average 28 degrees above normal. Multiple stations reported the month’s low temperature of -8 degrees on the 12th and 21st, on average 22 degrees below normal.

Heating Degree Day Totals

Home heating requirements, as estimated by heating degree day totals, averaged
21% more than last December and 8% less than normal. Thus far this heating season, heating degree day totals are running 1% more than last year at this time and 16% less than normal.

Precipitation

Most of the precipitation that fell during the month was rain as below-average snowfall was reported statewide. Much of western Iowa experienced precipitation deficits in the 0.50 to 1.00 inch range. Pockets of northeast and southeast Iowa observed above-average totals with the wettest conditions near the Iowa-Missouri border; many stations registered totals nearing 1.50-2.00 inches. Monthly precipitation totals ranged from 0.15 inch in Holstein (Ida County) to 4.68 inches at a Community Collaborative Rain, Hail and Snow (CoCoRaHS) network gauge in Bloomfield (Davis County). The statewide average snowfall was 2.3 inches, 5.6 inches below normal. Decorah (Winneshiek County) and Fayette (Fayette County) reported the highest monthly snowfall of 5.6 inches.

US Drought Monitor

As of the first week of December, drought conditions covered 60% of Iowa with D0 (Abnormally Dry) conditions over 33% of Iowa. Drought coverage by category was as follows: D1 (Moderate Drought) – 59%, D2 (Severe Drought) – 1%. Overall drought and dryness in Iowa improved over portions of Iowa with removal of D0 and D1 over southern and northeast Iowa. The current categorical breakdown is: D0 – 23%, D1 – 56%, D2 – 1% and D3 – 35%. 

Justin M. Glisan, Ph.D.
State Climatologist of Iowa
Iowa Dept. of Agriculture & Land Stewardship
Wallace State Office Bldg.
Des Moines, IA 50319
Telephone; (515) 281-8981
E-mail: Justin.Glisan@IowaAgriculture.gov

* Departures are computed from 1991-2020 normals.
The weather data in this report are based upon information collected by the U. S. Dept. of Commerce, NOAA National Weather Service.