Normal, Illinois climate: Normal weather by month, frost dates and records
Normal's normal year runs from 16°F January nights to 86°F July afternoons, with 39.4 inches of precipitation and 20 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.6°C, January lows of −9°C, July highs of 30°C, 1,001 mm of precipitation a year.
- NOAA stationNormal (4 mi NE)
- Station IDUSC00116200
- Location40.55°N 88.95°W
- Elevation790 ft (241 m)
- Population53,304
On October 23, the normal high in Normal is 62°F and the normal low 39°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 Normal.
- Jan 33° 16°
- Feb 38° 19°
- Mar 50° 28°
- Apr 63° 38°
- May 74° 50°
- Jun 83° 60°
- Jul 86° 63°
- Aug 84° 61°
- Sep 79° 53°
- Oct 66° 42°
- Nov 50° 31°
- Dec 38° 21°
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 Normal each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 16°F. The most precipitation falls in May (4.81 in), the least in February (1.99 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 33°F | 16°F | 24.5°F | 2.43 | 7.5 | 9 | <1 | 28 | 9 h 30 min |
| February | 38°F | 19°F | 28.5°F | 1.99 | 5.5 | 8 | <1 | 25 | 10 h 40 min |
| March | 50°F | 28°F | 38.8°F | 2.61 | 2.2 | 10 | <1 | 22 | 11 h 50 min |
| April | 63°F | 38°F | 50.3°F | 3.72 | 0.5 | 12 | <1 | 8 | 13 h 10 min |
| May | 74°F | 50°F | 61.9°F | 4.81 | 0.0 | 12 | 1 | 1 | 14 h 20 min |
| June | 83°F | 60°F | 71.6°F | 4.08 | 0.0 | 11 | 7 | <1 | 15 h |
| July | 86°F | 63°F | 74.5°F | 4.12 | 0.0 | 8 | 9 | <1 | 14 h 50 min |
| August | 84°F | 61°F | 72.6°F | 3.83 | 0.0 | 9 | 6 | <1 | 13 h 50 min |
| September | 79°F | 53°F | 65.9°F | 3.22 | 0.0 | 8 | 3 | <1 | 12 h 30 min |
| October | 66°F | 42°F | 53.7°F | 3.48 | 0.0 | 9 | <1 | 5 | 11 h 10 min |
| November | 50°F | 31°F | 40.5°F | 2.80 | 0.8 | 9 | <1 | 18 | 10 h |
| December | 38°F | 21°F | 29.8°F | 2.30 | 3.6 | 9 | <1 | 27 | 9 h 20 min |
| Year (annual) | 62°F | 40°F | 51.1°F | 39.39 | 20.1 | 113 | 26 | 133 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 1°C | −9°C | −4.2°C | 62 mm | 19 cm |
| February | 3°C | −7°C | −1.9°C | 51 mm | 14 cm |
| March | 10°C | −2°C | 3.8°C | 66 mm | 6 cm |
| April | 17°C | 3°C | 10.2°C | 94 mm | 1 cm |
| May | 23°C | 10°C | 16.6°C | 122 mm | 0 cm |
| June | 29°C | 16°C | 22.0°C | 104 mm | 0 cm |
| July | 30°C | 17°C | 23.6°C | 105 mm | 0 cm |
| August | 29°C | 16°C | 22.6°C | 97 mm | 0 cm |
| September | 26°C | 12°C | 18.8°C | 82 mm | 0 cm |
| October | 19°C | 5°C | 12.1°C | 88 mm | 0 cm |
| November | 10°C | −1°C | 4.7°C | 71 mm | 2 cm |
| December | 3°C | −6°C | −1.2°C | 58 mm | 9 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00116200; 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 Normal?
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 (8).
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 USC00116200.
When is the last frost in Normal?
In Normal, the last spring frost (32°F) comes after April 25 in half of years and after May 11 in one year in ten; the first autumn frost comes before October 16 in half of years and before October 2 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 251 year in 10 after May 11; 9 in 10 after April 11
- First autumn frost, half of years before
- October 161 year in 10 before October 2; 9 in 10 before October 29
NOAA puts the median frost-free season at 172 days, and the season without a hard freeze (28°F) at 195 days.
A hard freeze (28°F) comes after April 14 in half of springs and before October 27 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Normal in zone 6a in ZIP code 61761. By the map's own method, the average of each year's coldest night over 1991-2020, Normal's NOAA station is in zone 6a: the coldest night of a typical year reaches −9°F (27 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 USC00116200; 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 Normal?
In a normal year in Normal, 26 days a year reach 90°F (1 of them 100°F or more), 133 nights fall to 32°F or colder and 113 days bring measurable precipitation.
- Days at 90°F or more
- 26a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 133a normal year
- Days that stay below freezing
- 38high of 32°F or less
- Days with 0.01 inch of precipitation
- 113a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1893) is 114°F, on July 15, 1936; the lowest is −24°F, on January 24, 1894.
The wettest calendar year on that record is 1993, with 63.35 in; the snowiest season is 1959–60, with 57.8 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00116200; records: ACIS (NOAA Regional Climate Centers), station USC00116200. Records use complete months only; a month missing more than three days is left out.
How sunny is Normal?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Normal, 4.0 kWh per square metre a day. July is the sunniest month (82%) and December the cloudiest (62%). Among the 459 U.S. places of 50,000 or more, that ranks tied 330th (with 21 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 64% | 1.9 |
| February | 67% | 2.7 |
| March | 67% | 3.7 |
| April | 71% | 4.8 |
| May | 72% | 5.5 |
| June | 79% | 6.3 |
| July | 82% | 6.3 |
| August | 81% | 5.5 |
| September | 81% | 4.6 |
| October | 72% | 3.1 |
| November | 69% | 2.1 |
| 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 Normal need?
A normal year in Normal brings 6,023 heating degree days, 12% more than the median U.S. place (5,373), and 978 cooling degree days, 8% 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 3,354 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,255 | 0 |
| February | 1,021 | 0 |
| March | 814 | 2 |
| April | 448 | 8 |
| May | 172 | 76 |
| June | 20 | 218 |
| July | 3 | 297 |
| August | 8 | 244 |
| September | 87 | 114 |
| October | 368 | 18 |
| November | 737 | 0 |
| December | 1,090 | 0 |
| Year (annual) | 6,023 | 978 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00116200. 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 Normal been warmer than normal lately?
2025 averaged 52.4°F, 1.3°F above the 1991-2020 normal of 51.1°F. 2 of the 2 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 52.0°F | +0.9°F | 46.38 | 20.7 |
| 2025 | 52.4°F | +1.3°F | 27.99 | 24.1 |
Over 38 complete years from 1978 to 2025, the station's annual mean temperature rose at a fitted 2.8°F per century (+0.16°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00116200; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Normal's climate compare?
Normal is warmer than 56 of the other 143 places with their own NOAA record in Illinois, and wetter than 61. Across the 7,247 U.S. stations with normals, its annual mean of 51.1°F is warmer than 45%.
In the Köppen classification computed from these normals, Normal 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 Normal share this climate record?
7 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.
- Le Roy, IL3,495 people · 18 mi SE
- Hudson, IL1,767 people · 4 mi NW
- Downs, IL1,185 people · 11 mi S
- Towanda, IL426 people · 3 mi E
- Kappa, IL233 people · 9 mi N
- Ellsworth, IL180 people · 14 mi SE
- Cooksville, IL153 people · 12 mi E
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 Normal's climate
What is the coldest month in Normal?
January, with a normal high of 33°F and a normal low of 16°F. The warmest is July (86°F by day, 63°F at night).
Does it snow in Normal?
Yes: 20 inches in a normal year, falling on 15 days with 0.1 inch or more, the most in January (7.5 inches).
What is the rainiest month in Normal?
May, with 4.81 in of precipitation in a normal year; the driest is February with 1.99 in.
What plant hardiness zone is Normal in?
The USDA's 2023 map puts Normal in zone 6a in ZIP code 61761. By the same method at Normal's NOAA station, the coldest night of a typical year reaches −9°F (27 years, 1991-2020): zone 6a.
How late can frost come in Normal?
In half of years the last 32°F night comes after April 25; in one year in ten it comes after May 11. Waiting until May 11 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Normal in OctoberThis month day by day, its records and recent years
- Illinois climateThe statewide normals and every place in the state
- Bloomington, IL9 miles from this station, 50.2°F a year
- Congerville, IL16 miles from this station, 52.0°F a year
- Chenoa, IL18 miles from this station, 50.5°F a year
- Minonk, IL25 miles from this station, 51.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made