McLeansboro, Illinois climate: Normal weather by month, frost dates and records
McLeansboro's normal year runs from 22°F January nights to 89°F July afternoons, with 47.1 inches of precipitation and 13 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 13.0°C, January lows of −5°C, July highs of 32°C, 1,196 mm of precipitation a year.
- NOAA stationMcLeansboro
- Station IDUSC00115515
- Location38.08°N 88.54°W
- Elevation446 ft (136 m)
- From the centerunder 1 mile
- Population2,593
On October 23, the normal high in McLeansboro is 67°F and the normal low 41°F, and the chance of measurable rain or snow is 29%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for McLeansboro.
- Jan 41° 22°
- Feb 46° 24°
- Mar 56° 34°
- Apr 68° 44°
- May 77° 55°
- Jun 85° 63°
- Jul 89° 66°
- Aug 88° 63°
- Sep 82° 55°
- Oct 70° 43°
- Nov 56° 33°
- Dec 45° 26°
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 McLeansboro each month?
July is the warmest month, with normal highs of 89°F; January the coldest, with normal lows of 22°F. The most precipitation falls in April (5.29 in), the least in August (2.57 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 41°F | 22°F | 31.6°F | 3.55 | 3.7 | 11 | <1 | 26 | 9 h 50 min |
| February | 46°F | 24°F | 35.2°F | 2.90 | 3.3 | 9 | <1 | 21 | 10 h 50 min |
| March | 56°F | 34°F | 45.0°F | 4.53 | 2.1 | 12 | <1 | 17 | 11 h 50 min |
| April | 68°F | 44°F | 55.5°F | 5.29 | 0.0 | 13 | <1 | 5 | 13 h 10 min |
| May | 77°F | 55°F | 65.8°F | 4.94 | 0.0 | 13 | 1 | <1 | 14 h 10 min |
| June | 85°F | 63°F | 74.0°F | 5.05 | 0.0 | 11 | 8 | <1 | 14 h 50 min |
| July | 89°F | 66°F | 77.5°F | 3.47 | 0.0 | 8 | 16 | <1 | 14 h 30 min |
| August | 88°F | 63°F | 75.5°F | 2.57 | 0.0 | 8 | 13 | <1 | 13 h 40 min |
| September | 82°F | 55°F | 68.6°F | 3.50 | 0.0 | 8 | 5 | <1 | 12 h 30 min |
| October | 70°F | 43°F | 56.8°F | 3.38 | 0.6 | 8 | <1 | 4 | 11 h 20 min |
| November | 56°F | 33°F | 44.5°F | 4.41 | 0.2 | 10 | <1 | 15 | 10 h 10 min |
| December | 45°F | 26°F | 35.4°F | 3.50 | 3.4 | 12 | <1 | 23 | 9 h 30 min |
| Year (annual) | 67°F | 44°F | 55.4°F | 47.09 | 13.3 | 121 | 43 | 110 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 5°C | −5°C | −0.2°C | 90 mm | 9 cm |
| February | 8°C | −4°C | 1.8°C | 74 mm | 8 cm |
| March | 14°C | 1°C | 7.2°C | 115 mm | 5 cm |
| April | 20°C | 6°C | 13.1°C | 134 mm | 0 cm |
| May | 25°C | 13°C | 18.8°C | 125 mm | 0 cm |
| June | 30°C | 17°C | 23.3°C | 128 mm | 0 cm |
| July | 32°C | 19°C | 25.3°C | 88 mm | 0 cm |
| August | 31°C | 17°C | 24.2°C | 65 mm | 0 cm |
| September | 28°C | 13°C | 20.3°C | 89 mm | 0 cm |
| October | 21°C | 6°C | 13.8°C | 86 mm | 2 cm |
| November | 13°C | 0°C | 6.9°C | 112 mm | 1 cm |
| December | 7°C | −4°C | 1.9°C | 89 mm | 9 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00115515; 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 McLeansboro?
Normal highs sit between 65°F and 85°F in April, May, September and October. Of those, October 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 USC00115515.
When is the last frost in McLeansboro?
In McLeansboro, the last spring frost (32°F) comes after April 11 in half of years and after April 26 in one year in ten; the first autumn frost comes before October 21 in half of years and before October 6 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 111 year in 10 after April 26; 9 in 10 after March 27
- First autumn frost, half of years before
- October 211 year in 10 before October 6; 9 in 10 before November 1
NOAA puts the median frost-free season at 190 days, and the season without a hard freeze (28°F) at 209 days.
A hard freeze (28°F) comes after April 1 in half of springs and before October 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts McLeansboro in zone 6b in ZIP code 62859, 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 USC00115515; 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 McLeansboro?
In a normal year in McLeansboro, 43 days a year reach 90°F (1 of them 100°F or more), 110 nights fall to 32°F or colder and 121 days bring measurable precipitation.
- Days at 90°F or more
- 43a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 110a normal year
- Days that stay below freezing
- 17high of 32°F or less
- Days with 0.01 inch of precipitation
- 121a normal year
- Days with 1 inch of snow or more
- 4a normal year
The highest temperature in this station's record (since 1893) is 113°F, on July 14, 1936; the lowest is −23°F, on January 18, 1930.
The wettest calendar year on that record is 1945, with 63.38 in; the snowiest season is 1911–12, with 39.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00115515; records: ACIS (NOAA Regional Climate Centers), station USC00115515. Records use complete months only; a month missing more than three days is left out.
How sunny is McLeansboro?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around McLeansboro, 4.2 kWh per square metre a day. August is the sunniest month (83%) and December the cloudiest (63%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 65% | 2.0 |
| February | 66% | 2.8 |
| March | 67% | 3.7 |
| April | 73% | 5.0 |
| May | 73% | 5.6 |
| June | 82% | 6.5 |
| July | 83% | 6.3 |
| August | 83% | 5.7 |
| September | 81% | 4.7 |
| October | 76% | 3.4 |
| November | 71% | 2.4 |
| December | 63% | 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 McLeansboro need?
A normal year in McLeansboro brings 4,746 heating degree days, 12% fewer than the median U.S. place (5,373), and 1,306 cooling degree days, 44% more than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 4,039 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,035 | 0 |
| February | 833 | 0 |
| March | 624 | 4 |
| April | 302 | 19 |
| May | 82 | 106 |
| June | 7 | 277 |
| July | 0 | 389 |
| August | 2 | 329 |
| September | 46 | 156 |
| October | 279 | 25 |
| November | 618 | 2 |
| December | 917 | 0 |
| Year (annual) | 4,746 | 1,306 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00115515. 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 McLeansboro's climate compare?
McLeansboro is warmer than 125 of the other 143 places with their own NOAA record in Illinois, and wetter than 126. Across the 7,247 U.S. stations with normals, its annual mean of 55.4°F is warmer than 62%.
In the Köppen classification computed from these normals, McLeansboro 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 McLeansboro share this climate record?
4 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.
- Dahlgren, IL493 people · 11 mi NW
- Broughton, IL179 people · 11 mi SE
- Belle Prairie City, IL46 people · 10 mi N
- Macedonia, IL29 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 McLeansboro's climate
What is the coldest month in McLeansboro?
January, with a normal high of 41°F and a normal low of 22°F. The warmest is July (89°F by day, 66°F at night).
Does it snow in McLeansboro?
Yes: 13 inches in a normal year, falling on 9 days with 0.1 inch or more, the most in January (3.7 inches).
What is the rainiest month in McLeansboro?
April, with 5.29 in of precipitation in a normal year; the driest is August with 2.57 in.
What plant hardiness zone is McLeansboro in?
The USDA's 2023 map puts McLeansboro in zone 6b in ZIP code 62859, the nearest ZIP area.
How late can frost come in McLeansboro?
In half of years the last 32°F night comes after April 11; in one year in ten it comes after April 26. Waiting until April 26 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Carmi, IL20 miles from this station, 55.0°F a year
- Benton, IL21 miles from this station, 56.3°F a year
- Fairfield, IL24 miles from this station, 57.1°F a year
- Harrisburg, IL24 miles from this station, 57.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made