Photo: Daniel Schwen · CC BY-SA 4.0Thomasboro’s winters are colder but less snowy than most of the U.S.
A typical July afternoon reaches 85°, a January night drops to 18°, and about 21 inches of snow falls in a normal winter.
A year in Thomasboro at a glance
Each month’s typical high and low, and what it brings.
What stands out about Thomasboro’s climate
Compared with towns across the U.S., with Thomasboro’s place in Illinois beside it.
What a year in Thomasboro feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 179 frost-free days a year
In half of years the last 32° night comes by April 21 and the first by October 18. Frost and day counts come from NOAA’s station at Rantoul, IL, 5 miles from the town’s center, at about the same height.
The 2023 USDA map puts Thomasboro’s center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −9°. 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 21 inches of snow a winter
Snow, measured at Champaign 3s, IL, falls mostly in January. Precipitation (rain plus melted snow) adds up to 39 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 123 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Thomasboro
83% of the work is heating. 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 Rantoul, IL.
Living with Thomasboro’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
179 frost-free days in zone 6a. 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 18.
Months with highs of 62–84° and lows of 40° or more: April, May, June, August, September and October. 0.0 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Thomasboro from natural hazards, river flooding is the largest share (41%); heat waves, cold waves, winter storms and ice storms together are 21%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Thomasboro and similar climates
TownRatings has no climate map of the towns around Thomasboro yet.
Climates most like Thomasboro’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 |
|---|---|---|---|---|
| Thomasboro, IL | 18° | 85° | 39" | 21" |
| Burlington, IA | 16° | 86° | 38" | 22" |
| Van Wert, OH | 19° | 84° | 39" | 17" |
| Bluffton, IN | 19° | 84° | 41" | 23" |
| Kirksville, MO | 17° | 86° | 41" | 19" |
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 Thomasboro averaged 1.2° warmer than the 1900s. The biggest change is in December (+2.1°).
A smaller shift than in 64% 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 Thomasboro compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Thomasboro’s place among Illinois’.
Thomasboro weather by month
Highs, lows and precipitation from NOAA’s grid at Thomasboro’s center; snow, wet days and snow on the ground from Champaign 3s, IL. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 34° | 18° | 2.3" | 6.5" | 10 | 12 | 18° – 37° |
| February | 39° | 22° | 2.0" | 5.8" | 9 | 9 | 18° – 41° |
| March | 50° | 30° | 2.6" | 2.5" | 11 | 2 | 34° – 55° |
| April | 64° | 40° | 4.0" | 0.3" | 12 | 0 | 45° – 58° |
| May | 74° | 52° | 4.4" | 0.0" | 13 | 0 | 57° – 71° |
| June | 83° | 61° | 4.6" | 0.0" | 11 | 0 | 67° – 76° |
| July | 85° | 64° | 4.3" | 0.0" | 10 | 0 | 69° – 81° |
| August | 84° | 62° | 3.5" | 0.0" | 9 | 0 | 67° – 79° |
| September | 79° | 54° | 3.1" | 0.0" | 8 | 0 | 61° – 71° |
| October | 66° | 43° | 3.3" | 0.0" | 10 | 0 | 50° – 60° |
| November | 51° | 32° | 3.1" | 0.9" | 10 | 1 | 34° – 49° |
| December | 39° | 23° | 2.2" | 4.8" | 10 | 6 | 17° – 41° |
| Year | 62° | 42° | 39.3" | 20.8" | 123 | 30 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 17° to 41°. June is the most reliable, staying within 8°.
Where Thomasboro’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 Thomasboro’s center.
- Snow: Champaign 3s, IL.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Rantoul, IL, 5 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 Thomasboro’s climate
What is the weather like in Thomasboro?
A typical July afternoon reaches 85°, a January night drops to 18°, and about 21 inches of snow falls in a normal winter. Colder January nights than 72% of U.S. towns; cooler July afternoons than 50% of U.S. towns.
How cold does it get in Thomasboro in winter?
January nights average 18°. About 131 nights a year reach 32° or below and 8 reach 0° or below. In the coldest January of the last 30 years the month averaged 18°.
How much snow does Thomasboro get?
About 21 inches in a normal winter at Champaign 3s, IL, most of it in January, with snow on the ground about 30 days a year.
How hot does it get in Thomasboro?
July, with a typical high of 85° and a low of 64°. About 34 days a year reach 90° (Rantoul, IL).
When is the first and last frost in Thomasboro?
In half of years the last spring frost (32°) comes by April 21 and the first fall frost by October 18, about 179 frost-free days, at Rantoul, IL.
What growing zone is Thomasboro in?
Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −9°.
What is the best time of year to visit Thomasboro?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June, August, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Thomasboro getting warmer?
Yes: 1991–2020 averaged 1.2° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 64% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Thomasboro.
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.