Dwight, Illinois climate: Normal weather by month, frost dates and records
Dwight's normal year runs from 14°F January nights to 84°F July afternoons, with 37.7 inches of precipitation and 23 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.6°C, January lows of −10°C, July highs of 29°C, 957 mm of precipitation a year.
- NOAA stationDwight
- Station IDUSC00112500
- Location41.11°N 88.41°W
- Elevation628 ft (191 m)
- From the centerunder 1 mile
- Population4,032
On October 23, the normal high in Dwight is 61°F and the normal low 38°F, and the chance of measurable rain or snow is 27%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Dwight.
- Jan 31° 14°
- Feb 35° 17°
- Mar 48° 27°
- Apr 61° 37°
- May 72° 49°
- Jun 81° 59°
- Jul 84° 62°
- Aug 82° 59°
- Sep 77° 51°
- Oct 64° 40°
- Nov 49° 29°
- Dec 36° 20°
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 Dwight each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 14°F. The most precipitation falls in May (4.85 in), the least in February (1.64 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 31°F | 14°F | 22.3°F | 1.96 | 7.9 | 7 | <1 | 29 | 9 h 30 min |
| February | 35°F | 17°F | 26.2°F | 1.64 | 4.9 | 6 | <1 | 26 | 10 h 40 min |
| March | 48°F | 27°F | 37.1°F | 2.55 | 3.5 | 8 | <1 | 23 | 11 h 50 min |
| April | 61°F | 37°F | 48.8°F | 3.54 | 0.6 | 11 | <1 | 9 | 13 h 20 min |
| May | 72°F | 49°F | 60.7°F | 4.85 | 0.0 | 11 | 1 | <1 | 14 h 30 min |
| June | 81°F | 59°F | 70.1°F | 4.60 | 0.0 | 9 | 4 | <1 | 15 h 10 min |
| July | 84°F | 62°F | 72.8°F | 3.90 | 0.0 | 8 | 5 | <1 | 14 h 50 min |
| August | 82°F | 59°F | 70.7°F | 3.68 | 0.0 | 8 | 3 | <1 | 13 h 50 min |
| September | 77°F | 51°F | 64.2°F | 3.25 | 0.0 | 7 | 2 | <1 | 12 h 30 min |
| October | 64°F | 40°F | 52.1°F | 3.19 | 0.0 | 8 | <1 | 6 | 11 h 10 min |
| November | 49°F | 29°F | 39.0°F | 2.58 | 0.8 | 8 | <1 | 19 | 10 h |
| December | 36°F | 20°F | 27.8°F | 1.95 | 5.6 | 8 | <1 | 28 | 9 h 10 min |
| Year (annual) | 60°F | 39°F | 49.3°F | 37.69 | 23.3 | 98 | 16 | 140 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −1°C | −10°C | −5.4°C | 50 mm | 20 cm |
| February | 2°C | −8°C | −3.2°C | 42 mm | 12 cm |
| March | 9°C | −3°C | 2.8°C | 65 mm | 9 cm |
| April | 16°C | 3°C | 9.3°C | 90 mm | 2 cm |
| May | 22°C | 10°C | 15.9°C | 123 mm | 0 cm |
| June | 27°C | 15°C | 21.2°C | 117 mm | 0 cm |
| July | 29°C | 17°C | 22.7°C | 99 mm | 0 cm |
| August | 28°C | 15°C | 21.5°C | 93 mm | 0 cm |
| September | 25°C | 11°C | 17.9°C | 83 mm | 0 cm |
| October | 18°C | 5°C | 11.2°C | 81 mm | 0 cm |
| November | 9°C | −1°C | 3.9°C | 66 mm | 2 cm |
| December | 2°C | −7°C | −2.3°C | 50 mm | 14 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00112500; 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 Dwight?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. 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 USC00112500.
When is the last frost in Dwight?
In Dwight, the last spring frost (32°F) comes after April 27 in half of years and after May 14 in one year in ten; the first autumn frost comes before October 15 in half of years and before September 30 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 271 year in 10 after May 14; 9 in 10 after April 14
- First autumn frost, half of years before
- October 151 year in 10 before September 30; 9 in 10 before October 27
NOAA puts the median frost-free season at 170 days, and the season without a hard freeze (28°F) at 192 days.
A hard freeze (28°F) comes after April 17 in half of springs and before October 25 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Dwight in zone 5b in ZIP code 60420, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Dwight's NOAA station is in zone 5b: the coldest night of a typical year reaches −11°F (28 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 USC00112500; 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 Dwight?
In a normal year in Dwight, 16 days a year reach 90°F, 140 nights fall to 32°F or colder and 98 days bring measurable precipitation.
- Days at 90°F or more
- 16a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 140a normal year
- Days that stay below freezing
- 47high of 32°F or less
- Days with 0.01 inch of precipitation
- 98a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1990) is 103°F, on July 14, 1995; the lowest is −22°F, on January 5, 1999.
The wettest calendar year on that record is 1993, with 51.75 in; the snowiest season is 2000–01, with 33.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00112500; records: ACIS (NOAA Regional Climate Centers), station USC00112500. Records use complete months only; a month missing more than three days is left out.
How sunny is Dwight?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Dwight, 3.9 kWh per square metre a day. July is the sunniest month (81%) and January the cloudiest (61%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 61% | 1.7 |
| February | 65% | 2.6 |
| March | 67% | 3.6 |
| April | 70% | 4.8 |
| May | 71% | 5.5 |
| June | 77% | 6.1 |
| July | 81% | 6.2 |
| August | 80% | 5.4 |
| September | 80% | 4.5 |
| October | 71% | 3.0 |
| November | 67% | 2.0 |
| December | 61% | 1.5 |
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 Dwight need?
A normal year in Dwight brings 6,462 heating degree days, 20% more than the median U.S. place (5,373), and 784 cooling degree days, 14% fewer 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 3,037 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,322 | 0 |
| February | 1,088 | 0 |
| March | 866 | 1 |
| April | 489 | 5 |
| May | 195 | 62 |
| June | 31 | 184 |
| July | 6 | 248 |
| August | 14 | 189 |
| September | 108 | 84 |
| October | 410 | 11 |
| November | 782 | 0 |
| December | 1,152 | 0 |
| Year (annual) | 6,462 | 784 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00112500. 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 Dwight been warmer than normal lately?
2025 averaged 50.7°F, 1.4°F above the 1991-2020 normal of 49.3°F. 3 of the 4 complete years since 2022 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2022 | 48.6°F | −0.7°F | 27.59 | 25.3 |
| 2023 | 51.6°F | +2.3°F | 32.66 | 7.1 |
| 2024 | 53.0°F | +3.7°F | 32.57 | 12.8 |
| 2025 | 50.7°F | +1.4°F | 32.33 | 22.4 |
Over 32 complete years from 1991 to 2025, the station's annual mean temperature rose at a fitted 3.7°F per century (+0.21°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00112500; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Dwight's climate compare?
Dwight is warmer than 21 of the other 143 places with their own NOAA record in Illinois, and wetter than 26. Across the 7,247 U.S. stations with normals, its annual mean of 49.3°F is warmer than 37%.
In the Köppen classification computed from these normals, Dwight 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 Dwight share this climate record?
13 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.
- Gardner, IL1,366 people · 8 mi NE
- Odell, IL983 people · 9 mi SW
- Essex, IL853 people · 13 mi NE
- Braceville, IL722 people · 11 mi NE
- South Wilmington, IL715 people · 8 mi NE
- Buckingham, IL238 people · 13 mi E
- Cabery, IL233 people · 13 mi SE
- Verona, IL207 people · 9 mi NW
- Reddick, IL195 people · 9 mi E
- Campus, IL140 people · 8 mi SE
- Emington, IL99 people · 10 mi S
- Kinsman, IL87 people · 10 mi NW
- East Brooklyn, IL79 people · 9 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 Dwight's climate
What is the coldest month in Dwight?
January, with a normal high of 31°F and a normal low of 14°F. The warmest is July (84°F by day, 62°F at night).
Does it snow in Dwight?
Yes: 23 inches in a normal year, falling on 10 days with 0.1 inch or more, the most in January (7.9 inches).
What is the rainiest month in Dwight?
May, with 4.85 in of precipitation in a normal year; the driest is February with 1.64 in.
What plant hardiness zone is Dwight in?
The USDA's 2023 map puts Dwight in zone 5b in ZIP code 60420, the nearest ZIP area. By the same method at Dwight's NOAA station, the coldest night of a typical year reaches −11°F (28 years, 1991-2020): zone 5b.
How late can frost come in Dwight?
In half of years the last 32°F night comes after April 27; in one year in ten it comes after May 14. Waiting until May 14 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Morris, IL18 miles from this station, 50.8°F a year
- Pontiac, IL20 miles from this station, 51.8°F a year
- Streator, IL21 miles from this station, 51.6°F a year
- Channahon, IL21 miles from this station, 51.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made