Photo: Brian Stansberry (photographer) · CC BY 4.0A middle-of-the-road climate: Colp is close to most U.S. towns on every count
The coldest hours of a January night bottom out at 25° on average. From frosty January to warm July, readings climb 64°. Precipitation is plentiful here, more than falls on 70% of U.S. towns. For walks and days out, April, May, September and October bring highs of 68–81°.
A year in Colp at a glance
Each month’s typical high and low, and what it brings.
What stands out about Colp’s climate
Compared with towns across the U.S., with Colp’s place in Illinois beside it.
What a year in Colp feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 195 frost-free days a year
In half of years the last 32° night comes by April 9 and the first by October 22. Frost and day counts come from NOAA’s station at Carbondale Sewage Plt, IL, 7 miles from the town’s center, at about the same height.
The 2023 USDA map puts Colp’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 1°. 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 11 inches of snow a winter
Snow, measured at Carbondale Sewage Plt, IL, falls mostly in February. Precipitation (rain plus melted snow) adds up to 47 inches a year; April 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 Colp
77% of the work is heating. Months averaging under 55° run from November through March.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Carbondale Sewage Plt, IL.
Living with Colp’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
195 frost-free days in zone 7a. The last frost comes by Apr 9 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 22.
Months with highs of 62–84° and lows of 40° or more: April, May, September and October.
Parks & trails →Of the yearly building losses FEMA expects in Colp from natural hazards, river flooding is the largest share (29%); heat waves, cold waves, winter storms and ice storms together are 20%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Colp and similar climates
TownRatings has no climate map of the towns around Colp yet.
Climates most like Colp’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 |
|---|---|---|---|---|
| Colp, IL | 25° | 88° | 47" | 11" |
| Aurora, MO | 24° | 89° | 47" | 12" |
| Shively, KY | 25° | 88° | 49" | 13" |
| Harrison, AR | 26° | 89° | 47" | 9.5" |
| Collegeville, PA | 23° | 88° | 47" | 13" |
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 Colp averaged 1.0° warmer than the 1900s. The biggest change is in February (+1.9°).
A smaller shift than in 80% 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 Colp compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Colp’s place among Illinois’.
Colp weather by month
Highs, lows and precipitation from NOAA’s grid at Colp’s center; snow, wet days and snow on the ground from Carbondale Sewage Plt, IL. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 41° | 25° | 3.2" | 3.2" | 10 | 27° – 42° |
| February | 46° | 28° | 3.0" | 4.0" | 9 | 25° – 46° |
| March | 57° | 36° | 4.3" | 1.3" | 12 | 39° – 60° |
| April | 68° | 45° | 5.4" | 0.0" | 12 | 50° – 62° |
| May | 77° | 55° | 5.1" | 0.0" | 13 | 61° – 73° |
| June | 85° | 64° | 4.4" | 0.0" | 10 | 69° – 79° |
| July | 88° | 68° | 3.9" | 0.0" | 9 | 72° – 84° |
| August | 87° | 65° | 3.2" | 0.0" | 9 | 71° – 83° |
| September | 81° | 57° | 3.3" | 0.0" | 8 | 65° – 76° |
| October | 70° | 46° | 3.6" | 0.2" | 9 | 54° – 63° |
| November | 56° | 36° | 4.1" | 0.0" | 10 | 39° – 52° |
| December | 45° | 28° | 3.4" | 2.7" | 11 | 23° – 46° |
| Year | 67° | 46° | 47.0" | 11.4" | 121 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 23° to 46°. October is the most reliable, staying within 9°.
Where Colp’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 Colp’s center.
- Snow: Carbondale Sewage Plt, IL.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Carbondale Sewage Plt, IL, 7 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 Colp’s climate
What is the weather like in Colp?
A typical July afternoon reaches 88°, a January night drops to 25°, and about 11 inches of snow falls in a normal winter. Milder January nights than 61% of U.S. towns; hotter July afternoons than 68% of U.S. towns.
How cold does it get in Colp in winter?
January nights average 25°. About 103 nights a year reach 32° or below and 2 reach 0° or below. In the coldest January of the last 30 years the month averaged 27°.
How much snow does Colp get?
About 11 inches in a normal winter at Carbondale Sewage Plt, IL, most of it in February.
How hot does it get in Colp?
July, with a typical high of 88° and a low of 68°. About 38 days a year reach 90° and 1 reach 100° (Carbondale Sewage Plt, IL).
When is the first and last frost in Colp?
In half of years the last spring frost (32°) comes by April 9 and the first fall frost by October 22, about 195 frost-free days, at Carbondale Sewage Plt, IL.
What growing zone is Colp in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 1°.
What is the best time of year to visit Colp?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Colp getting warmer?
Yes: 1991–2020 averaged 1.0° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 80% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Colp.
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.