Oak Run, IL climate
Oak Run has chilly winters and warm summers. A typical July afternoon reaches 85°, a January night drops to 15°, and about 25 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Oak Run feels like
Winter
Spring
Summer
Fall
Oak Run 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 | 31° | 15° | 1.7" | 6.4" | 9 | 14 | 15° – 36° |
| February | 36° | 19° | 1.9" | 7.7" | 9 | 11 | 14° – 38° |
| March | 49° | 29° | 2.4" | 3.4" | 10 | 3 | 31° – 53° |
| April | 62° | 39° | 3.8" | 0.4" | 12 | 0 | 42° – 58° |
| May | 73° | 51° | 5.0" | 0 | 14 | 0 | 56° – 69° |
| June | 82° | 60° | 4.6" | 0 | 12 | 0 | 68° – 75° |
| July | 85° | 64° | 4.0" | 0 | 10 | 0 | 69° – 80° |
| August | 83° | 61° | 3.7" | 0 | 10 | 0 | 67° – 78° |
| September | 77° | 53° | 3.7" | 0 | 8 | 0 | 60° – 70° |
| October | 64° | 42° | 3.0" | 0.2" | 10 | 0 | 48° – 58° |
| November | 49° | 31° | 2.5" | 1.4" | 8 | 1 | 32° – 50° |
| December | 36° | 21° | 2.1" | 5.9" | 9 | 9 | 14° – 38° |
| Year | 61° | 40° | 38.4" | 25.4" | 119 | 38 |
“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 Oak Run
Oak Run gets 38 inches of rain and melted snow a year. May is the wettest month and January the driest. Rain or snow falls on about 119 days a year. Snow covers the ground about 38 days of the year.
About 181 frost-free days a year
In half of years the last 32° night comes by April 21 and the first one by October 20. That leaves about 181 frost-free days for gardens, longer than 54% of U.S. towns.
Heating and cooling a home in Oak Run
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Oak Run, 87% of that work is heating and 13% 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.
How Oak Run 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 Oak Run averaged 0.8° warmer than the 1900s. The biggest change is in December (+2.0°). The shift is smaller than in 84% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Oak Run’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 14° to 38°. June is the most reliable, staying within 7°.
Common questions about Oak Run’s climate
What is the coldest month in Oak Run?
January, with a typical high of 31° and a low of 15°.
What is the hottest month in Oak Run?
July, with a typical high of 85° and a low of 64°. About 13 days a year reach 90°.
How much snow does Oak Run get?
About 25 inches in a normal winter, most of it in February.
When is the first frost in Oak Run?
In half of years the first 32° night comes by October 20, and the last spring frost by April 21.
What is the rainiest month in Oak Run?
May, with 5.0 inches of rain and melted snow. The year totals 38 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Oak Run itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Knoxville, IL (9 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.