Photo: Daytripper07 (Uploads) · CC BY 2.5Bunker Hill’s winters are colder but less snowy than most of the U.S.
A typical July afternoon reaches 87°, a January night drops to 22°, and about 17 inches of snow falls in a normal winter.
A year in Bunker Hill at a glance
Each month’s typical high and low, and what it brings.
What stands out about Bunker Hill’s climate
Compared with towns across the U.S., with Bunker Hill’s place in Illinois beside it.
What a year in Bunker Hill feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 214 frost-free days a year
In half of years the last 32° night comes by April 4 and the first by November 5. Frost and day counts come from NOAA’s station at Alton - Melvin Price L&d, IL, 16 miles from the town’s center, 240 ft lower.
The 2023 USDA map puts Bunker Hill’s center in zone 6b: the coldest night of a typical winter, averaged over 1991–2020, reaches about −2°. 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 Carlinville, IL, falls mostly in January. Precipitation (rain plus melted snow) adds up to 42 inches a year; May is the wettest month and February the driest. Rain or snow falls on about 105 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Bunker Hill
77% of the work is heating. Months averaging under 55° run from November 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 Alton - Melvin Price L&d, IL.
Living with Bunker Hill’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
214 frost-free days in zone 6b. The last frost comes by Apr 4 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Nov 5.
Months with highs of 62–84° and lows of 40° or more: April, May, June, September and October.
Parks & trails →Of the yearly building losses FEMA expects in Bunker Hill from natural hazards, river flooding is the largest share (30%); heat waves, cold waves, winter storms and ice storms together are 22%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Bunker Hill and similar climates
TownRatings has no climate map of the towns around Bunker Hill yet.
Climates most like Bunker Hill’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 |
|---|---|---|---|---|
| Bunker Hill, IL | 22° | 87° | 42" | 17" |
| Pleasant Hill, MO | 21° | 88° | 43" | 17" |
| Reading, OH | 23° | 87° | 44" | 16" |
| Louisburg, KS | 21° | 88° | 41" | 14" |
| Front Royal, VA | 24° | 87° | 41" | 21" |
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 Bunker Hill averaged 0.8° warmer than the 1900s. The biggest change is in December (+2.0°).
A smaller shift than in 89% 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 Bunker Hill compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Bunker Hill’s place among Illinois’.
Bunker Hill weather by month
Highs, lows and precipitation from NOAA’s grid at Bunker Hill’s center; snow, wet days and snow on the ground from Carlinville, IL. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 38° | 22° | 2.5" | 5.8" | 9 | 10 | 23° – 41° |
| February | 43° | 26° | 2.2" | 4.7" | 7 | 5 | 23° – 44° |
| March | 54° | 34° | 3.2" | 2.3" | 9 | 2 | 36° – 57° |
| April | 66° | 44° | 4.8" | 0.0" | 11 | 0 | 47° – 60° |
| May | 75° | 55° | 4.9" | 0.0" | 11 | 0 | 60° – 72° |
| June | 84° | 64° | 4.3" | 0.0" | 9 | 0 | 69° – 77° |
| July | 87° | 67° | 4.1" | 0.0" | 8 | 0 | 72° – 84° |
| August | 86° | 65° | 3.5" | 0.0" | 7 | 0 | 70° – 81° |
| September | 80° | 57° | 3.3" | 0.0" | 8 | 0 | 63° – 74° |
| October | 68° | 46° | 3.3" | 0.0" | 9 | 0 | 51° – 63° |
| November | 53° | 35° | 3.4" | 0.9" | 8 | 1 | 37° – 52° |
| December | 42° | 26° | 2.6" | 2.8" | 8 | 3 | 20° – 43° |
| Year | 65° | 45° | 42.0" | 16.5" | 105 | 20 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 20° to 43°. June is the most reliable, staying within 9°.
Where Bunker Hill’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 Bunker Hill’s center.
- Snow: Carlinville, IL.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Alton - Melvin Price L&d, IL, 16 miles from the town’s center, 240 ft lower; 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 Bunker Hill’s climate
What is the weather like in Bunker Hill?
A typical July afternoon reaches 87°, a January night drops to 22°, and about 17 inches of snow falls in a normal winter. Colder January nights than 51% of U.S. towns; hotter July afternoons than 62% of U.S. towns.
How cold does it get in Bunker Hill in winter?
January nights average 22°. About 85 nights a year reach 32° or below and 1 reach 0° or below. In the coldest January of the last 30 years the month averaged 23°.
How much snow does Bunker Hill get?
About 17 inches in a normal winter at Carlinville, IL, most of it in January, with snow on the ground about 20 days a year.
How hot does it get in Bunker Hill?
July, with a typical high of 87° and a low of 67°. About 29 days a year reach 90° (Alton - Melvin Price L&d, IL).
When is the first and last frost in Bunker Hill?
In half of years the last spring frost (32°) comes by April 4 and the first fall frost by November 5, about 214 frost-free days, at Alton - Melvin Price L&d, IL.
What growing zone is Bunker Hill in?
Zone 6b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −2°.
What is the best time of year to visit Bunker Hill?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Bunker Hill getting warmer?
Yes: 1991–2020 averaged 0.8° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 89% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Bunker Hill.
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.