Winchester, Illinois climate: Normal weather by month, frost dates and records
Winchester's normal year runs from 18°F January nights to 87°F July afternoons, with 40.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.6°C, January lows of −8°C, July highs of 30°C, 1,026 mm of precipitation a year.
- NOAA stationWinchester
- Station IDUSC00119331
- Location39.63°N 90.45°W
- Elevation551 ft (168 m)
- From the centerunder 1 mile
- Population1,510
On October 23, the normal high in Winchester is 65°F and the normal low 40°F, and the chance of measurable rain or snow is 24%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Winchester.
- Jan 36° 18°
- Feb 41° 21°
- Mar 53° 31°
- Apr 65° 41°
- May 75° 52°
- Jun 84° 62°
- Jul 87° 65°
- Aug 86° 63°
- Sep 80° 54°
- Oct 68° 43°
- Nov 53° 32°
- Dec 41° 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 Winchester each month?
July is the warmest month, with normal highs of 87°F; January the coldest, with normal lows of 18°F. The most precipitation falls in June (4.99 in), the least in February (2.14 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 36°F | 18°F | 26.7°F | 2.26 | 7 | <1 | 28 | 9 h 40 min |
| February | 41°F | 21°F | 31.2°F | 2.14 | 7 | <1 | 25 | 10 h 40 min |
| March | 53°F | 31°F | 41.5°F | 3.06 | 9 | <1 | 19 | 11 h 50 min |
| April | 65°F | 41°F | 53.0°F | 4.40 | 10 | <1 | 4 | 13 h 10 min |
| May | 75°F | 52°F | 63.5°F | 4.81 | 11 | 1 | <1 | 14 h 20 min |
| June | 84°F | 62°F | 72.7°F | 4.99 | 9 | 6 | <1 | 15 h |
| July | 87°F | 65°F | 76.0°F | 3.97 | 7 | 12 | <1 | 14 h 40 min |
| August | 86°F | 63°F | 74.5°F | 3.47 | 7 | 10 | <1 | 13 h 50 min |
| September | 80°F | 54°F | 66.9°F | 3.03 | 7 | 4 | <1 | 12 h 30 min |
| October | 68°F | 43°F | 55.1°F | 3.09 | 8 | <1 | 5 | 11 h 10 min |
| November | 53°F | 32°F | 42.1°F | 2.75 | 6 | <1 | 15 | 10 h |
| December | 41°F | 23°F | 32.1°F | 2.43 | 8 | <1 | 26 | 9 h 20 min |
| Year (annual) | 64°F | 42°F | 52.9°F | 40.40 | 94 | 34 | 122 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 2°C | −8°C | −2.9°C | 57 mm |
| February | 5°C | −6°C | −0.4°C | 54 mm |
| March | 11°C | −1°C | 5.3°C | 78 mm |
| April | 18°C | 5°C | 11.7°C | 112 mm |
| May | 24°C | 11°C | 17.5°C | 122 mm |
| June | 29°C | 17°C | 22.6°C | 127 mm |
| July | 30°C | 18°C | 24.4°C | 101 mm |
| August | 30°C | 17°C | 23.6°C | 88 mm |
| September | 27°C | 12°C | 19.4°C | 77 mm |
| October | 20°C | 6°C | 12.8°C | 78 mm |
| November | 12°C | 0°C | 5.6°C | 70 mm |
| December | 5°C | −5°C | 0.1°C | 62 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, White Hall (14 miles away), gets 18 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00119331; 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 Winchester?
Normal highs sit between 65°F and 85°F in April, May, June, 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 USC00119331.
When is the last frost in Winchester?
In Winchester, the last spring frost (32°F) comes after April 18 in half of years and after May 5 in one year in ten; the first autumn frost comes before October 20 in half of years and before October 5 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 181 year in 10 after May 5; 9 in 10 after April 3
- First autumn frost, half of years before
- October 201 year in 10 before October 5; 9 in 10 before October 31
NOAA puts the median frost-free season at 183 days, and the season without a hard freeze (28°F) at 206 days.
A hard freeze (28°F) comes after April 5 in half of springs and before October 29 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Winchester in zone 6a in ZIP code 62694, the nearest ZIP area.
Frost dates for every NOAA station in Illinois · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00119331; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 Winchester?
In a normal year in Winchester, 34 days a year reach 90°F (2 of them 100°F or more), 122 nights fall to 32°F or colder and 94 days bring measurable precipitation.
- Days at 90°F or more
- 34a normal year
- Days at 100°F or more
- 2a normal year
- Nights at 32°F or colder
- 122a normal year
- Days that stay below freezing
- 31high of 32°F or less
- Days with 0.01 inch of precipitation
- 94a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00119331.
How sunny is Winchester?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Winchester, 4.1 kWh per square metre a day. July is the sunniest month (83%) and December the cloudiest (65%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 66% | 2.0 |
| February | 67% | 2.8 |
| March | 68% | 3.7 |
| April | 72% | 4.9 |
| May | 73% | 5.6 |
| June | 80% | 6.3 |
| July | 83% | 6.4 |
| August | 81% | 5.6 |
| September | 82% | 4.8 |
| October | 75% | 3.3 |
| November | 72% | 2.3 |
| December | 65% | 1.7 |
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 Winchester need?
A normal year in Winchester brings 5,485 heating degree days, 2% more than the median U.S. place (5,373), and 1,130 cooling degree days, 25% 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 3,673 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,185 | 0 |
| February | 946 | 0 |
| March | 731 | 3 |
| April | 371 | 13 |
| May | 132 | 85 |
| June | 14 | 245 |
| July | 1 | 341 |
| August | 4 | 296 |
| September | 68 | 126 |
| October | 328 | 22 |
| November | 686 | 1 |
| December | 1,020 | 0 |
| Year (annual) | 5,485 | 1,130 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00119331. 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 Winchester's climate compare?
Winchester is warmer than 92 of the other 143 places with their own NOAA record in Illinois, and wetter than 79. Across the 7,247 U.S. stations with normals, its annual mean of 52.9°F is warmer than 53%.
In the Köppen classification computed from these normals, Winchester 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 Winchester share this climate record?
10 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.
- Bluffs, IL597 people · 9 mi NW
- Chapin, IL462 people · 10 mi N
- Alsey, IL183 people · 5 mi S
- Glasgow, IL107 people · 6 mi S
- Naples, IL97 people · 12 mi NW
- Exeter, IL84 people · 6 mi N
- Merritt, IL75 people · 6 mi N
- Oxville, IL27 people · 8 mi NW
- Riggston, IL27 people · 4 mi N
- Florence, IL17 people · 9 mi W
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 Winchester's climate
What is the coldest month in Winchester?
January, with a normal high of 36°F and a normal low of 18°F. The warmest is July (87°F by day, 65°F at night).
Does it snow in Winchester?
Yes. NOAA publishes no 1991-2020 snowfall normal for Winchester's NOAA station; the nearest record that keeps one, White Hall (14 miles away), records 18 inches of snow in a normal year.
What is the rainiest month in Winchester?
June, with 4.99 in of precipitation in a normal year; the driest is February with 2.14 in.
What plant hardiness zone is Winchester in?
The USDA's 2023 map puts Winchester in zone 6a in ZIP code 62694, the nearest ZIP area.
How late can frost come in Winchester?
In half of years the last 32°F night comes after April 18; in one year in ten it comes after May 5. Waiting until May 5 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Jacksonville, IL13 miles from this station, 52.8°F a year
- White Hall, IL14 miles from this station, 52.9°F a year
- Pittsfield, IL19 miles from this station, 53.8°F a year
- Perry, IL23 miles from this station, 53.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made