Carbondale, Illinois climate: Normal weather by month, frost dates and records
Carbondale's normal year runs from 25°F January nights to 88°F July afternoons, with 44.0 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 13.6°C, January lows of −4°C, July highs of 31°C, 1,118 mm of precipitation a year.
- NOAA stationCarbondale Southern Illinois Airport
- Station IDUSW00093810
- Location37.78°N 89.25°W
- Elevation406 ft (124 m)
- From the center4 miles
- Population22,223
On October 14, the normal high in Carbondale is 71°F and the normal low 45°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 Carbondale.
- Jan 42° 25°
- Feb 47° 28°
- Mar 57° 36°
- Apr 68° 45°
- May 77° 55°
- Jun 86° 64°
- Jul 88° 68°
- Aug 87° 65°
- Sep 81° 56°
- Oct 70° 45°
- Nov 56° 35°
- Dec 46° 28°
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 Carbondale each month?
July is the warmest month, with normal highs of 88°F; January the coldest, with normal lows of 25°F. The most precipitation falls in April (5.34 in), the least in February (2.61 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. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 42°F | 25°F | 33.2°F | 2.79 | 8 | <1 | 25 | 9 h 50 min |
| February | 47°F | 28°F | 37.5°F | 2.61 | 9 | <1 | 19 | 10 h 50 min |
| March | 57°F | 36°F | 46.5°F | 4.14 | 11 | <1 | 11 | 11 h 50 min |
| April | 68°F | 45°F | 56.7°F | 5.34 | 11 | <1 | 3 | 13 h 10 min |
| May | 77°F | 55°F | 66.2°F | 4.98 | 14 | 1 | <1 | 14 h 10 min |
| June | 86°F | 64°F | 74.9°F | 4.11 | 11 | 10 | <1 | 14 h 50 min |
| July | 88°F | 68°F | 78.0°F | 3.61 | 12 | 14 | <1 | 14 h 30 min |
| August | 87°F | 65°F | 76.0°F | 3.05 | 12 | 11 | <1 | 13 h 40 min |
| September | 81°F | 56°F | 68.3°F | 2.85 | 11 | 4 | <1 | 12 h 30 min |
| October | 70°F | 45°F | 57.4°F | 3.54 | 10 | <1 | 3 | 11 h 20 min |
| November | 56°F | 35°F | 45.6°F | 3.87 | 10 | <1 | 13 | 10 h 10 min |
| December | 46°F | 28°F | 37.0°F | 3.12 | 10 | <1 | 22 | 9 h 30 min |
| Year (annual) | 67°F | 46°F | 56.4°F | 44.01 | 130 | 41 | 95 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 5°C | −4°C | 0.7°C | 71 mm |
| February | 8°C | −2°C | 3.1°C | 66 mm |
| March | 14°C | 2°C | 8.1°C | 105 mm |
| April | 20°C | 7°C | 13.7°C | 136 mm |
| May | 25°C | 13°C | 19.0°C | 126 mm |
| June | 30°C | 18°C | 23.8°C | 104 mm |
| July | 31°C | 20°C | 25.6°C | 92 mm |
| August | 31°C | 18°C | 24.4°C | 77 mm |
| September | 27°C | 13°C | 20.2°C | 72 mm |
| October | 21°C | 7°C | 14.1°C | 90 mm |
| November | 13°C | 2°C | 7.6°C | 98 mm |
| December | 8°C | −2°C | 2.8°C | 79 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. Carbondale's own co-op station Carbondale Sewage Plant does: 11 inches of snow in a normal year (see the other stations below).
Source: NOAA NCEI 1991-2020 monthly normals, station USW00093810; 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 Carbondale?
Normal highs sit between 65°F and 85°F in April, May, September and October. Of those, October has the fewest days with rain (10).
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 USW00093810.
When is the last frost in Carbondale?
In Carbondale, the last spring frost (32°F) comes after April 9 in half of years and after April 25 in one year in ten; the first autumn frost comes before October 22 in half of years and before October 8 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 91 year in 10 after April 25; 9 in 10 after March 24
- First autumn frost, half of years before
- October 221 year in 10 before October 8; 9 in 10 before November 1
NOAA puts the median frost-free season at 195 days, and the season without a hard freeze (28°F) at 217 days.
A hard freeze (28°F) comes after March 30 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Carbondale in zone 7a across its 2 ZIP code areas (7a in 62901, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Carbondale's NOAA station is in zone 7a: the coldest night of a typical year reaches 0°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 USW00093810; 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.
What hardiness zone is each Carbondale ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Carbondale's 2 ZIP code areas are all in zone 7a. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Carbondale?
In a normal year in Carbondale, 41 days a year reach 90°F (1 of them 100°F or more), 95 nights fall to 32°F or colder and 130 days bring measurable precipitation.
- Days at 90°F or more
- 41a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 95a normal year
- Days that stay below freezing
- 15high of 32°F or less
- Days with 0.01 inch of precipitation
- 130a normal year
The highest temperature in Carbondale's official record (kept by the National Weather Service since 1898) is 113°F, on August 9, 1930; the lowest is −25°F, on January 11, 1977.
The wettest calendar year on that record is 1945, with 74.50 in; the snowiest season is 1911–12, with 50.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00093810; records: ACIS (NOAA Regional Climate Centers), NWS threaded record MDHthr. Records use complete months only; a month missing more than three days is left out.
How sunny is Carbondale?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Carbondale, 4.3 kWh per square metre a day. July is the sunniest month (82%) and December the cloudiest (64%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 66% | 2.2 |
| February | 65% | 2.8 |
| March | 67% | 3.8 |
| April | 73% | 5.1 |
| May | 75% | 5.7 |
| June | 82% | 6.5 |
| July | 82% | 6.3 |
| August | 82% | 5.7 |
| September | 81% | 4.8 |
| October | 76% | 3.5 |
| November | 72% | 2.5 |
| December | 64% | 1.9 |
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 Carbondale need?
A normal year in Carbondale brings 4,460 heating degree days, 17% fewer than the median U.S. place (5,373), and 1,370 cooling degree days, 51% more than the median (908). Five months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 4,161 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 984 | 0 |
| February | 770 | 0 |
| March | 577 | 4 |
| April | 275 | 24 |
| May | 81 | 118 |
| June | 4 | 302 |
| July | 0 | 401 |
| August | 1 | 342 |
| September | 49 | 146 |
| October | 267 | 31 |
| November | 584 | 2 |
| December | 870 | 0 |
| Year (annual) | 4,460 | 1,370 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00093810. 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 Carbondale been warmer than normal lately?
2025 averaged 57.9°F, 1.5°F above the 1991-2020 normal of 56.4°F. 3 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 57.4°F | +1.0°F | 43.78 |
| 2022 | 56.1°F | −0.3°F | – |
| 2023 | 58.9°F | +2.5°F | 37.12 |
| 2025 | 57.9°F | +1.5°F | 37.84 |
Source: observed years: ACIS, station USW00093810. A year counts only with all twelve months complete.
How does Carbondale's climate compare?
Carbondale is warmer than 133 of the other 143 places with their own NOAA record in Illinois, and wetter than 114. Across the 7,247 U.S. stations with normals, its annual mean of 56.4°F is warmer than 65%.
In the Köppen classification computed from these normals, Carbondale is Cfa: temperate, 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 Carbondale share this climate record?
19 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.
- Marion, IL17,021 people · 17 mi E
- Herrin, IL12,253 people · 12 mi E
- Murphysboro, IL7,044 people · 5 mi W
- Carterville, IL5,821 people · 9 mi E
- Cambria, IL1,793 people · 7 mi E
- Crainville, IL1,493 people · 11 mi E
- De Soto, IL1,408 people · 3 mi NE
- Energy, IL956 people · 12 mi E
- Harrison, IL948 people · 5 mi W
- Hurst, IL750 people · 7 mi NE
- Ava, IL547 people · 15 mi NW
- Altenburg, MO337 people · 21 mi SW
- Blairsville, IL279 people · 7 mi E
- Frohna, MO246 people · 22 mi SW
- Bush, IL237 people · 8 mi NE
- Vergennes, IL236 people · 10 mi NW
- Spillertown, IL177 people · 18 mi E
- Colp, IL175 people · 10 mi E
- Gorham, IL171 people · 13 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.
What do Carbondale's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Carbondale. This page uses Carbondale Southern Illinois Airport; the other differs by site and elevation:
| Station | From the center | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Carbondale Sewage Plant USC00111265 | 3 mi E | 390 ft | 56.0°F | 23°F | 88°F | 49.0 | 11 | April 9 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Carbondale's climate
What is the coldest month in Carbondale?
January, with a normal high of 42°F and a normal low of 25°F. The warmest is July (88°F by day, 68°F at night).
Does it snow in Carbondale?
Yes. NOAA publishes no 1991-2020 snowfall normal for Carbondale's NOAA station; Carbondale's own co-op station Carbondale Sewage Plant records 11 inches of snow in a normal year.
What is the rainiest month in Carbondale?
April, with 5.34 in of precipitation in a normal year; the driest is February with 2.61 in.
What plant hardiness zone is Carbondale in?
The USDA's 2023 map puts Carbondale in zone 7a across its 2 ZIP code areas (7a in 62901, the largest). By the same method at Carbondale's NOAA station, the coldest night of a typical year reaches 0°F (21 years, 1991-2020): zone 7a.
How late can frost come in Carbondale?
In half of years the last 32°F night comes after April 9; in one year in ten it comes after April 25. Waiting until April 25 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Carbondale in OctoberThis month day by day, its records and recent years
- Illinois climateThe statewide normals and every place in the state
- Du Quoin, IL15 miles from this station, 56.0°F a year
- Anna, IL21 miles from this station, 58.5°F a year
- Rend Lake Dam, IL23 miles from this station, 55.9°F a year
- Benton, IL25 miles from this station, 56.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made