Congerville, Illinois climate: Normal weather by month, frost dates and records
Congerville's normal year runs from 17°F January nights to 86°F July afternoons, with 37.5 inches of precipitation and 22 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.1°C, January lows of −8°C, July highs of 30°C, 952 mm of precipitation a year.
- NOAA stationCongerville (2 mi NW)
- Station IDUSC00111836
- Location40.62°N 89.24°W
- Elevation640 ft (195 m)
- From the center2 miles
- Population503
On October 22, the normal high in Congerville is 64°F and the normal low 40°F, and the chance of measurable rain or snow is 30%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Congerville.
- Jan 33° 17°
- Feb 38° 21°
- Mar 50° 31°
- Apr 63° 41°
- May 74° 52°
- Jun 83° 61°
- Jul 86° 65°
- Aug 84° 63°
- Sep 80° 55°
- Oct 67° 43°
- Nov 51° 32°
- Dec 39° 23°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Congerville each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 17°F. The most precipitation falls in May (4.77 in), the least in February (1.76 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 33°F | 17°F | 25.2°F | 2.05 | 6.8 | 9 | <1 | 28 | 9 h 30 min |
| February | 38°F | 21°F | 29.4°F | 1.76 | 5.2 | 7 | <1 | 25 | 10 h 40 min |
| March | 50°F | 31°F | 40.7°F | 2.44 | 2.8 | 9 | <1 | 21 | 11 h 50 min |
| April | 63°F | 41°F | 52.0°F | 3.77 | 0.8 | 11 | <1 | 7 | 13 h 10 min |
| May | 74°F | 52°F | 62.7°F | 4.77 | 0.0 | 12 | 1 | 1 | 14 h 20 min |
| June | 83°F | 61°F | 71.9°F | 4.05 | 0.0 | 10 | 5 | <1 | 15 h |
| July | 86°F | 65°F | 75.2°F | 3.86 | 0.0 | 9 | 8 | <1 | 14 h 50 min |
| August | 84°F | 63°F | 73.4°F | 3.74 | 0.0 | 9 | 5 | <1 | 13 h 50 min |
| September | 80°F | 55°F | 67.1°F | 3.21 | 0.0 | 7 | 4 | <1 | 12 h 30 min |
| October | 67°F | 43°F | 54.6°F | 3.14 | 0.0 | 10 | <1 | 6 | 11 h 10 min |
| November | 51°F | 32°F | 41.7°F | 2.64 | 1.5 | 8 | <1 | 18 | 10 h |
| December | 39°F | 23°F | 30.7°F | 2.04 | 5.2 | 8 | <1 | 27 | 9 h 20 min |
| Year (annual) | 62°F | 42°F | 52.0°F | 37.47 | 22.3 | 110 | 24 | 134 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 1°C | −8°C | −3.8°C | 52 mm | 17 cm |
| February | 3°C | −6°C | −1.4°C | 45 mm | 13 cm |
| March | 10°C | −1°C | 4.8°C | 62 mm | 7 cm |
| April | 17°C | 5°C | 11.1°C | 96 mm | 2 cm |
| May | 23°C | 11°C | 17.1°C | 121 mm | 0 cm |
| June | 28°C | 16°C | 22.2°C | 103 mm | 0 cm |
| July | 30°C | 18°C | 24.0°C | 98 mm | 0 cm |
| August | 29°C | 17°C | 23.0°C | 95 mm | 0 cm |
| September | 27°C | 13°C | 19.5°C | 82 mm | 0 cm |
| October | 19°C | 6°C | 12.6°C | 80 mm | 0 cm |
| November | 11°C | 0°C | 5.4°C | 67 mm | 4 cm |
| December | 4°C | −5°C | −0.7°C | 52 mm | 13 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00111836; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Congerville?
Normal highs sit between 65°F and 85°F in May, June, August, September and October. Of those, September has the fewest days with rain (7).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00111836.
When is the last frost in Congerville?
In Congerville, the last spring frost (32°F) comes after April 21 in half of years and after May 7 in one year in ten; the first autumn frost comes before October 17 in half of years and before October 3 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 211 year in 10 after May 7; 9 in 10 after April 7
- First autumn frost, half of years before
- October 171 year in 10 before October 3; 9 in 10 before October 30
NOAA puts the median frost-free season at 178 days, and the season without a hard freeze (28°F) at 198 days.
A hard freeze (28°F) comes after April 9 in half of springs and before October 27 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Congerville in zone 5b in ZIP code 61729, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Congerville's NOAA station is in zone 5b: the coldest night of a typical year reaches −13°F (19 complete years).
Frost dates for every NOAA station in Illinois · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00111836; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Congerville?
In a normal year in Congerville, 24 days a year reach 90°F, 134 nights fall to 32°F or colder and 110 days bring measurable precipitation.
- Days at 90°F or more
- 24a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 134a normal year
- Days that stay below freezing
- 36high of 32°F or less
- Days with 0.01 inch of precipitation
- 110a normal year
- Days with 1 inch of snow or more
- 8a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00111836.
How sunny is Congerville?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Congerville, 4.1 kWh per square metre a day. July is the sunniest month (83%) and December the cloudiest (62%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 64% | 1.9 |
| February | 67% | 2.8 |
| March | 68% | 3.7 |
| April | 71% | 4.9 |
| May | 72% | 5.6 |
| June | 79% | 6.3 |
| July | 83% | 6.4 |
| August | 81% | 5.6 |
| September | 81% | 4.7 |
| October | 73% | 3.2 |
| November | 70% | 2.2 |
| December | 62% | 1.6 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Congerville need?
A normal year in Congerville brings 5,752 heating degree days, 7% more than the median U.S. place (5,373), and 1,067 cooling degree days, 18% more than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,532 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,235 | 0 |
| February | 998 | 0 |
| March | 756 | 3 |
| April | 405 | 13 |
| May | 156 | 86 |
| June | 20 | 226 |
| July | 3 | 317 |
| August | 5 | 265 |
| September | 70 | 132 |
| October | 345 | 24 |
| November | 698 | 1 |
| December | 1,063 | 0 |
| Year (annual) | 5,752 | 1,067 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00111836. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Congerville been warmer than normal lately?
2025 averaged 52.2°F, 0.2°F above the 1991-2020 normal of 52.0°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 52.4°F | +0.4°F | 40.38 | 20.9 |
| 2022 | 50.5°F | −1.5°F | 33.06 | 29.5 |
| 2023 | 53.3°F | +1.3°F | 31.56 | 13.5 |
| 2024 | 53.8°F | +1.8°F | 38.85 | 8.6 |
| 2025 | 52.2°F | +0.2°F | 29.60 | 18.7 |
Source: observed years: ACIS, station USC00111836. A year counts only with all twelve months complete.
How does Congerville's climate compare?
Congerville is warmer than 74 of the other 143 places with their own NOAA record in Illinois, and wetter than 20. Across the 7,247 U.S. stations with normals, its annual mean of 52.0°F is warmer than 49%.
In the Köppen classification computed from these normals, Congerville is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Congerville share this climate record?
11 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Morton, IL17,557 people · 12 mi W
- Washington, IL15,857 people · 12 mi NW
- Eureka, IL5,189 people · 7 mi N
- Metamora, IL3,870 people · 14 mi NW
- Mackinaw, IL1,848 people · 9 mi SW
- Heritage Lake, IL1,708 people · 7 mi SW
- Goodfield, IL958 people · 1 mi NW
- Hopedale, IL802 people · 17 mi SW
- Deer Creek, IL650 people · 5 mi W
- Carlock, IL569 people · 6 mi SE
- Secor, IL337 people · 10 mi NE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Congerville's climate
What is the coldest month in Congerville?
January, with a normal high of 33°F and a normal low of 17°F. The warmest is July (86°F by day, 65°F at night).
Does it snow in Congerville?
Yes: 22 inches in a normal year, falling on 15 days with 0.1 inch or more, the most in January (6.8 inches).
What is the rainiest month in Congerville?
May, with 4.77 in of precipitation in a normal year; the driest is February with 1.76 in.
What plant hardiness zone is Congerville in?
The USDA's 2023 map puts Congerville in zone 5b in ZIP code 61729, the nearest ZIP area. By the same method at Congerville's NOAA station, the coldest night of a typical year reaches −13°F (19 years, 1991-2020): zone 5b.
How late can frost come in Congerville?
In half of years the last 32°F night comes after April 21; in one year in ten it comes after May 7. Waiting until May 7 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Bloomington, IL12 miles from this station, 50.2°F a year
- Normal, IL16 miles from this station, 51.1°F a year
- Minonk, IL23 miles from this station, 51.3°F a year
- Peoria, IL24 miles from this station, 52.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made