Watseka, Illinois climate: Normal weather by month, frost dates and records
Watseka's normal year runs from 16°F January nights to 85°F July afternoons, with 38.4 inches of precipitation and 17 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.4°C, January lows of −9°C, July highs of 29°C, 976 mm of precipitation a year.
- NOAA stationWatseka (2 mi NW)
- Station IDUSC00119021
- Location40.79°N 87.75°W
- Elevation620 ft (189 m)
- From the center2 miles
- Population4,495
On October 23, the normal high in Watseka is 62°F and the normal low 39°F, and the chance of measurable rain or snow is 32%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Watseka.
- Jan 33° 16°
- Feb 37° 18°
- Mar 50° 29°
- Apr 62° 38°
- May 74° 50°
- Jun 82° 60°
- Jul 85° 63°
- Aug 83° 60°
- Sep 79° 52°
- Oct 66° 41°
- Nov 51° 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 Watseka each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 16°F. The most precipitation falls in June (5.02 in), the least in February (1.98 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 33°F | 16°F | 24.1°F | 2.07 | 5.4 | 10 | <1 | 28 | 9 h 30 min |
| February | 37°F | 18°F | 27.9°F | 1.98 | 4.7 | 8 | <1 | 25 | 10 h 40 min |
| March | 50°F | 29°F | 39.1°F | 2.42 | 1.6 | 10 | <1 | 21 | 11 h 50 min |
| April | 62°F | 38°F | 50.3°F | 3.65 | 0.3 | 12 | <1 | 8 | 13 h 20 min |
| May | 74°F | 50°F | 61.8°F | 4.41 | 0.0 | 12 | 1 | 1 | 14 h 30 min |
| June | 82°F | 60°F | 70.9°F | 5.02 | 0.0 | 11 | 4 | <1 | 15 h |
| July | 85°F | 63°F | 73.7°F | 4.20 | 0.0 | 9 | 5 | <1 | 14 h 50 min |
| August | 83°F | 60°F | 71.6°F | 3.50 | 0.0 | 9 | 3 | <1 | 13 h 50 min |
| September | 79°F | 52°F | 65.4°F | 3.19 | 0.0 | 9 | 2 | <1 | 12 h 30 min |
| October | 66°F | 41°F | 53.6°F | 3.24 | 0.0 | 10 | <1 | 6 | 11 h 10 min |
| November | 51°F | 31°F | 40.8°F | 2.65 | 0.7 | 10 | <1 | 18 | 10 h |
| December | 38°F | 21°F | 29.7°F | 2.10 | 4.4 | 10 | <1 | 27 | 9 h 20 min |
| Year (annual) | 62°F | 40°F | 50.8°F | 38.43 | 17.1 | 121 | 16 | 133 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −9°C | −4.4°C | 53 mm | 14 cm |
| February | 3°C | −8°C | −2.3°C | 50 mm | 12 cm |
| March | 10°C | −2°C | 3.9°C | 61 mm | 4 cm |
| April | 17°C | 3°C | 10.2°C | 93 mm | 1 cm |
| May | 23°C | 10°C | 16.6°C | 112 mm | 0 cm |
| June | 28°C | 15°C | 21.6°C | 128 mm | 0 cm |
| July | 29°C | 17°C | 23.2°C | 107 mm | 0 cm |
| August | 28°C | 16°C | 22.0°C | 89 mm | 0 cm |
| September | 26°C | 11°C | 18.6°C | 81 mm | 0 cm |
| October | 19°C | 5°C | 12.0°C | 82 mm | 0 cm |
| November | 10°C | −1°C | 4.9°C | 67 mm | 2 cm |
| December | 3°C | −6°C | −1.3°C | 53 mm | 11 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00119021; 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 Watseka?
Normal highs sit between 65°F and 85°F in May, June, July, August, September and October. Of those, September has the fewest days with rain (9).
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 USC00119021.
When is the last frost in Watseka?
In Watseka, the last spring frost (32°F) comes after April 24 in half of years and after May 10 in one year in ten; the first autumn frost comes before October 16 in half of years and before October 1 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 241 year in 10 after May 10; 9 in 10 after April 10
- First autumn frost, half of years before
- October 161 year in 10 before October 1; 9 in 10 before October 28
NOAA puts the median frost-free season at 174 days, and the season without a hard freeze (28°F) at 196 days.
A hard freeze (28°F) comes after April 12 in half of springs and before October 26 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Watseka in zone 5b in ZIP code 60970, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Watseka's NOAA station is in zone 5b: the coldest night of a typical year reaches −11°F (21 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 USC00119021; 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 Watseka?
In a normal year in Watseka, 16 days a year reach 90°F, 133 nights fall to 32°F or colder and 121 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
- 133a normal year
- Days that stay below freezing
- 40high of 32°F or less
- Days with 0.01 inch of precipitation
- 121a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1893) is 106°F, on July 22, 1901; the lowest is −28°F, on January 5, 1999.
The wettest calendar year on that record is 1993, with 60.66 in; the snowiest season is 1981–82, with 45.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00119021; records: ACIS (NOAA Regional Climate Centers), station USC00119021. Records use complete months only; a month missing more than three days is left out.
How sunny is Watseka?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Watseka, 4.0 kWh per square metre a day. July is the sunniest month (81%) and December the cloudiest (60%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 62% | 1.8 |
| February | 66% | 2.7 |
| March | 67% | 3.6 |
| April | 70% | 4.8 |
| May | 72% | 5.5 |
| June | 79% | 6.3 |
| July | 81% | 6.3 |
| August | 81% | 5.6 |
| September | 80% | 4.6 |
| October | 72% | 3.1 |
| November | 69% | 2.1 |
| December | 60% | 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 Watseka need?
A normal year in Watseka brings 6,047 heating degree days, 13% more than the median U.S. place (5,373), and 892 cooling degree days, 2% 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 3,256 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,268 | 0 |
| February | 1,039 | 0 |
| March | 806 | 2 |
| April | 449 | 8 |
| May | 169 | 71 |
| June | 24 | 202 |
| July | 4 | 275 |
| August | 9 | 214 |
| September | 90 | 103 |
| October | 371 | 17 |
| November | 726 | 0 |
| December | 1,094 | 0 |
| Year (annual) | 6,047 | 892 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00119021. 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.
How does Watseka's climate compare?
Watseka is warmer than 49 of the other 143 places with their own NOAA record in Illinois, and wetter than 42. Across the 7,247 U.S. stations with normals, its annual mean of 50.8°F is warmer than 44%.
In the Köppen classification computed from these normals, Watseka 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 Watseka share this climate record?
6 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.
- Clifton, IL1,295 people · 14 mi NW
- Morocco, IN1,081 people · 19 mi NE
- Ashkum, IL716 people · 12 mi NW
- Crescent City, IL528 people · 6 mi W
- Martinton, IL321 people · 9 mi N
- Woodland, IL237 people · 6 mi S
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 Watseka's climate
What is the coldest month in Watseka?
January, with a normal high of 33°F and a normal low of 16°F. The warmest is July (85°F by day, 63°F at night).
Does it snow in Watseka?
Yes: 17 inches in a normal year, falling on 13 days with 0.1 inch or more, the most in January (5.4 inches).
What is the rainiest month in Watseka?
June, with 5.02 in of precipitation in a normal year; the driest is February with 1.98 in.
What plant hardiness zone is Watseka in?
The USDA's 2023 map puts Watseka in zone 5b in ZIP code 60970, the nearest ZIP area. By the same method at Watseka's NOAA station, the coldest night of a typical year reaches −11°F (21 years, 1991-2020): zone 5b.
How late can frost come in Watseka?
In half of years the last 32°F night comes after April 24; in one year in ten it comes after May 10. Waiting until May 10 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Kentland, IN17 miles from this station, 51.0°F a year
- Piper City, IL22 miles from this station, 51.9°F a year
- Hoopeston, IL23 miles from this station, 52.2°F a year
- Boswell, IN24 miles from this station, 49.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made