Sun Prairie, WI climate
Sun Prairie has cold, snowy winters and pleasant summers. A typical July afternoon reaches 82°, a January night drops to 10°, and about 52 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decade2° warmer than normal today. The forecast high is 68°, and a typical Sep 30 in Sun Prairie peaks around 67°.Live forecast: National Weather Service · Normal: NOAA 1991–2020
What a year in Sun Prairie feels like
Winter
Spring
Summer
Fall
Sun Prairie weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 27° | 10° | 1.4" | 13.7" | 11 | 24 | 7° – 31° |
| February | 31° | 14° | 1.4" | 12.8" | 10 | 22 | 11° – 34° |
| March | 43° | 24° | 2.2" | 7.0" | 11 | 10 | 26° – 49° |
| April | 57° | 35° | 3.7" | 2.6" | 13 | 1 | 37° – 52° |
| May | 69° | 46° | 4.2" | 0.1" | 13 | 0 | 51° – 64° |
| June | 79° | 57° | 5.4" | 0 | 12 | 0 | 65° – 72° |
| July | 82° | 61° | 4.4" | 0 | 10 | 0 | 65° – 79° |
| August | 80° | 58° | 4.0" | 0 | 9 | 0 | 64° – 75° |
| September | 73° | 50° | 3.6" | 0 | 9 | 0 | 55° – 67° |
| October | 60° | 39° | 2.9" | 0.6" | 10 | 0 | 45° – 56° |
| November | 45° | 28° | 2.2" | 3.0" | 10 | 3 | 27° – 46° |
| December | 32° | 17° | 1.6" | 12.0" | 10 | 16 | 10° – 35° |
| Year | 56° | 37° | 36.9" | 51.8" | 126 | 78 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Sun Prairie
Sun Prairie gets 37 inches of rain and melted snow a year. June is the wettest month and February the driest. Rain or snow falls on about 126 days a year. Snow covers the ground about 78 days of the year.
About 160 frost-free days a year
In half of years the last 32° night comes by May 1 and the first one by October 10. That leaves about 160 frost-free days for gardens, shorter than 71% of U.S. towns.
Heating and cooling a home in Sun Prairie
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Sun Prairie, 92% of that work is heating and 8% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Sun Prairie and its neighbors
Sun Prairie borders 5 towns with climate data. January nights across them vary by 0.7°. Windsor has the coldest January nights (10°) and Burke the hottest July afternoons (83°). Sun Prairie’s January low is 10° and its July high 82°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Sun Prairie compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Sun Prairie averaged 1.4° warmer than the 1900s. The biggest change is in December (+2.9°). The shift is larger than in 66% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Sun Prairie’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. December swings the most: between 1991 and 2020 its average temperature ranged from 10° to 35°. June is the most reliable, staying within 7°.
Common questions about Sun Prairie’s climate
What is the coldest month in Sun Prairie?
January, with a typical high of 27° and a low of 10°.
What is the hottest month in Sun Prairie?
July, with a typical high of 82° and a low of 61°. About 9 days a year reach 90°.
How much snow does Sun Prairie get?
About 52 inches in a normal winter, most of it in January.
When is the first frost in Sun Prairie?
In half of years the first 32° night comes by October 10, and the last spring frost by May 1.
What is the rainiest month in Sun Prairie?
June, with 5.4 inches of rain and melted snow. The year totals 37 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Sun Prairie itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Madison Dane Rgnl Airport, WI (6 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.