Photo: Mlw126 · CC BY-SA 4.0Oak Run’s winters are colder and snowier than most of the U.S.
A typical July afternoon reaches 85°, a January night drops to 15°, and about 25 inches of snow falls in a normal winter.
A year in Oak Run at a glance
Each month’s typical high and low, and what it brings.
What stands out about Oak Run’s climate
Compared with towns across the U.S., with Oak Run’s place in Illinois beside it.
What a year in Oak Run feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 181 frost-free days a year
In half of years the last 32° night comes by April 21 and the first by October 20. Frost and day counts come from NOAA’s station at Knoxville, IL, 9 miles from the town’s center, at about the same height.
The 2023 USDA map puts Oak Run’s center in zone 5b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −11°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 25 inches of snow a winter
Snow, measured at Knoxville, IL, falls mostly in February. Precipitation (rain plus melted snow) adds up to 38 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 119 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Oak Run
87% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Knoxville, IL.
Living with Oak Run’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
181 frost-free days in zone 5b. The last frost comes by Apr 21 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 20.
Months with highs of 62–84° and lows of 40° or more: May, June, August, September and October.
Parks & trails →Of the yearly building losses FEMA expects in Oak Run from natural hazards, river flooding is the largest share (33%); heat waves, cold waves, winter storms and ice storms together are 22%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Oak Run and similar climates
TownRatings has no climate map of the towns around Oak Run yet.
Climates most like Oak Run’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Oak Run, IL | 15° | 85° | 38" | 25" |
| Osceola, IA | 13° | 85° | 37" | 28" |
| Hobart, IN | 17° | 83° | 39" | 27" |
| Bryan, OH | 18° | 84° | 37" | 29" |
| Claverack, NY | 16° | 84° | 42" | 31" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
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°).
A smaller shift than in 90% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Oak Run compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Oak Run’s place among Illinois’.
Oak Run weather by month
Highs, lows and precipitation from NOAA’s grid at Oak Run’s center; snow, wet days and snow on the ground from Knoxville, IL. 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" | 0.0" | 14 | 0 | 56° – 69° |
| June | 82° | 60° | 4.6" | 0.0" | 12 | 0 | 68° – 75° |
| July | 85° | 64° | 4.0" | 0.0" | 10 | 0 | 69° – 80° |
| August | 83° | 61° | 3.7" | 0.0" | 10 | 0 | 67° – 78° |
| September | 77° | 53° | 3.7" | 0.0" | 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 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 14° to 38°. June is the most reliable, staying within 7°.
Where Oak Run’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Oak Run’s center.
- Snow: Knoxville, IL.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Knoxville, IL, 9 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Oak Run’s climate
What is the weather like in Oak Run?
A typical July afternoon reaches 85°, a January night drops to 15°, and about 25 inches of snow falls in a normal winter. Colder January nights than 84% of U.S. towns; cooler July afternoons than 55% of U.S. towns.
How cold does it get in Oak Run in winter?
January nights average 15°. About 135 nights a year reach 32° or below and 12 reach 0° or below. In the coldest January of the last 30 years the month averaged 15°.
How much snow does Oak Run get?
About 25 inches in a normal winter at Knoxville, IL, most of it in February, with snow on the ground about 38 days a year.
How hot does it get in Oak Run?
July, with a typical high of 85° and a low of 64°. About 13 days a year reach 90° (Knoxville, IL).
When is the first and last frost in Oak Run?
In half of years the last spring frost (32°) comes by April 21 and the first fall frost by October 20, about 181 frost-free days, at Knoxville, IL.
What growing zone is Oak Run in?
Zone 5b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −11°.
What is the best time of year to visit Oak Run?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, August, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Oak Run getting warmer?
Yes: 1991–2020 averaged 0.8° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 90% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Oak Run.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.