Photo: Augiejv · CC BY-SA 3.0Midwinter lows in Gilman sink below those of 76% of U.S. towns
Midsummer highs settle at about 85°. It is a dry place: less rain and snow fall here than on 64% of U.S. towns. Compared with 1901–2000, the average now sits 1.3° higher. Tender plants can go out after about April 25; in half of years the first frost comes by October 20.
A year in Gilman at a glance
Each month’s typical high and low, and what it brings.
What stands out about Gilman’s climate
Compared with towns across the U.S., with Gilman’s place in Illinois beside it.
What a year in Gilman feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 175 frost-free days a year
In half of years the last 32° night comes by April 25 and the first by October 20. Frost and day counts come from NOAA’s station at Piper City, IL, 10 miles from the town’s center, at about the same height.
The 2023 USDA map puts Gilman’s center in zone 5b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −10°. 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 17 inches of snow a winter
Snow, measured at Watseka 2 Nw, 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 121 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Gilman
85% 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 Piper City, IL.
Living with Gilman’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
175 frost-free days in zone 5b. The last frost comes by Apr 25 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 Gilman from natural hazards, river flooding is the largest share (45%); heat waves, cold waves, winter storms and ice storms together are 41%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Gilman and similar climates
TownRatings has no climate map of the towns around Gilman yet.
Climates most like Gilman’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 |
|---|---|---|---|---|
| Gilman, IL | 17° | 85° | 39" | 17" |
| Van Wert, OH | 19° | 84° | 39" | 17" |
| Fort Madison, IA | 17° | 86° | 39" | 18" |
| Kirksville, MO | 17° | 86° | 41" | 19" |
| Monaca, PA | 21° | 84° | 40" | 20" |
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 Gilman averaged 1.3° warmer than the 1900s. The biggest change is in December (+2.6°).
A smaller shift than in 55% 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 Gilman compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Gilman’s place among Illinois’.
Gilman weather by month
Highs, lows and precipitation from NOAA’s grid at Gilman’s center; snow, wet days and snow on the ground from Watseka 2 Nw, IL. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 33° | 17° | 2.2" | 5.4" | 10 | 16° – 38° |
| February | 38° | 21° | 1.9" | 4.7" | 8 | 16° – 40° |
| March | 50° | 30° | 2.5" | 1.6" | 10 | 32° – 55° |
| April | 63° | 39° | 3.7" | 0.3" | 12 | 43° – 57° |
| May | 74° | 51° | 4.4" | 0.0" | 12 | 56° – 70° |
| June | 83° | 60° | 4.8" | 0.0" | 11 | 67° – 75° |
| July | 85° | 63° | 4.5" | 0.0" | 9 | 69° – 80° |
| August | 83° | 61° | 3.6" | 0.0" | 9 | 67° – 78° |
| September | 78° | 54° | 3.3" | 0.0" | 9 | 61° – 71° |
| October | 66° | 42° | 3.2" | 0.0" | 10 | 50° – 59° |
| November | 50° | 32° | 2.8" | 0.7" | 10 | 33° – 49° |
| December | 38° | 22° | 2.2" | 4.4" | 10 | 16° – 41° |
| Year | 62° | 41° | 39.0" | 17.1" | 121 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 16° to 41°. June is the most reliable, staying within 9°.
Where Gilman’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 Gilman’s center.
- Snow: Watseka 2 Nw, IL.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Piper City, IL, 10 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 Gilman’s climate
What is the weather like in Gilman?
A typical July afternoon reaches 85°, a January night drops to 17°, and about 17 inches of snow falls in a normal winter. Colder January nights than 76% of U.S. towns; cooler July afternoons than 52% of U.S. towns.
How cold does it get in Gilman in winter?
January nights average 17°. About 134 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 16°.
How much snow does Gilman get?
About 17 inches in a normal winter at Watseka 2 Nw, IL, most of it in January.
How hot does it get in Gilman?
July, with a typical high of 85° and a low of 63°. About 28 days a year reach 90° and 1 reach 100° (Piper City, IL).
When is the first and last frost in Gilman?
In half of years the last spring frost (32°) comes by April 25 and the first fall frost by October 20, about 175 frost-free days, at Piper City, IL.
What growing zone is Gilman in?
Zone 5b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −10°.
What is the best time of year to visit Gilman?
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 Gilman getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 55% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Gilman.
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.