Illinois

West Frankfort, Illinois Climate

NOAA 1991-2020 normals for Rend Lake Dam, 16.6 km from West Frankfort

The warmest month is July, with an average high of 88°F; the coldest is January, with an average low of 22°F. A normal year brings 46.0 in of precipitation and 9.8 in of snow.

Temperature through the year

The normal daily high and low and the record for every date at Marion Regional (MWA), since 1894. The line marks today.

Normal daily high and low temperature at West Frankfort through the year, in °F, with the record for each date.-50050100150JanFebMarAprMayJunJulAugSepOctNovDec
  • Normal low
  • Normal high
  • Record high
  • Record low

Normals for Sep 24

Normal high
78°F
Normal low
55°F
Record high
97°Fin 1935
Record low
30°Fin 1928
Chance of a wet day
24%
Daylight
12 h 04 min

Month by month

Averages for 1991-2020. Wet days have at least 0.01 inch of precipitation. Freeze nights have a low of 32°F or colder; degree days are on a 65°F base. Each month links to its own page.

MonthAvg highAvg lowRecord highRecord lowPrecipitationWet daysSnowfallFreeze nightsHeating DDCooling DD
January40°F22°F76°F (1943)-25°F (1977)3.18 in7.82.3 in25.81,0630
February44°F25°F79°F (1982)-22°F (1951)2.80 in7.82.9 in21.08620
March55°F35°F93°F (1910)-11°F (1978)4.21 in10.41.4 in11.46222
April68°F45°F92°F (1915)20°F (1954)5.43 in11.20.1 in2.327421
May76°F56°F101°F (1911)29°F (1903)5.07 in12.70.0 in0.091128
June86°F65°F108°F (2012)39°F (1917)4.48 in9.40.0 in0.03316
July88°F68°F112°F (1936)42°F (1972)3.96 in7.80.0 in0.00411
August87°F66°F113°F (1930)41°F (1902)3.35 in7.20.0 in0.01362
September81°F58°F108°F (1925)20°F (1899)3.22 in7.10.0 in0.042168
October69°F46°F96°F (1922)16°F (1952)3.44 in8.00.3 in2.026640
November55°F35°F88°F (1933)-1°F (1929)3.97 in7.70.1 in13.65923
December44°F27°F77°F (1982)-14°F (1989)2.89 in8.02.7 in23.89190
Year66°F46°F46.00 in1059.8 in1004,7341,449

Precipitation

Rain and melted snow together. The chance of a wet day is the share of days with at least 0.01 inch of precipitation.

46.0 in in a normal year, most in April.

Chance of a wet day

The chance of at least 0.01 inch of precipitation on each date at West Frankfort, in percent, and of at least 0.1 inch of snowfall.01020304050JanFebMarAprMayJunJulAugSepOctNovDec
  • Chance of a wet day
  • Chance of snowfall

Snow

NOAA 1991-2020 snowfall normals for Plumfield, 6.9 km away; Rend Lake Dam keeps no snowfall normals.

9.8 in of snow in a normal year.

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Rend Lake Dam. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around April 4 and the first fall freeze around October 27, a growing season of about 204 days.

Median at 36°F
last April 15, first October 18
Median at 32°F
last April 4, first October 27
Median at 28°F
last March 26, first November 5

Frost dates, growing season and degree days

Humidity and comfort

NASA POWER reanalysis, 1991-2020, for the grid cell around West Frankfort.

The muggiest month is July, when 75 percent of days are muggy or worse, with a mean dew point of 65°F or more.

MonthDew pointHumidityDryComfortableHumidMuggyOppressiveMiserable
January26°F84%98%2%0%0%0%0%
February30°F82%98%2%0%0%0%0%
March38°F79%91%5%4%0%0%0%
April49°F77%69%15%12%4%0%0%
May59°F79%34%16%18%25%7%0%
June66°F78%5%12%20%25%31%5%
July69°F76%2%8%14%26%39%10%
August65°F71%7%14%20%31%25%3%
September57°F68%40%17%18%18%6%0%
October47°F70%76%13%7%4%0%0%
November37°F77%94%4%2%0%0%0%
December30°F83%98%2%0%0%0%0%

Comfort is judged by the day's mean dew point: dry below 55°F, comfortable to 60°F, humid to 65°F, muggy to 70°F, oppressive to 75°F, miserable above.

Clouds

Average share of the sky covered, from satellite (CERES and GEWEX SRB) by way of NASA POWER, 1991-2020.

The clearest month is September, with the sky 46 percent covered on average; the cloudiest is February, at 68 percent.

Wind

The mean wind speed over the whole day, from the MERRA-2 reanalysis by way of NASA POWER. Gusts run well above it.

The windiest month is March, averaging 11.4 mph at 10 meters (33 feet) above the ground.

Daylight and sunshine

The longest day is Jun 17, with 14 h 48 min of daylight; the shortest is Dec 17, with 9 h 32 min.

Hours of daylight at West Frankfort through the year.0510152025JanFebMarAprMayJunJulAugSepOctNovDec
  • Day length

Solar energy

Average daily sunshine reaching the ground on a flat surface, in kilowatt-hours per square meter, clouds included.

Sunrise and sunset calendar

How Franklin County is running

NOAA NCEI Climate at a Glance, from the nClimGrid analysis of every station, updated early each month. A rank of 1 is the highest or lowest of all years since 1895.

August 2026 in Franklin County: 77.4°F (+1.6 °F against 1991-2020), the 28th warmest in 132 years on record.

August 2026 in Franklin County: 2.35 in (-0.91 in against 1991-2020), the 40th driest in 132 years on record.

January to August 2026 in Franklin County: 60.2°F (+2.1 °F against 1991-2020), the 5th warmest in 132 years on record.

January to August 2026 in Franklin County: 21.22 in (-11.48 in against 1991-2020), the 12th driest in 132 years on record.

Warmest August
83.5°F in 1936
Coolest August
69.9°F in 1915
Wettest August
10.64 in in 1946
Driest August
0.31 in in 1909

Every year since 1895

Each year's average temperature in Franklin County against the 1991-2020 average, in °F, 1895 to 2025.-4-20+2+41900192019401960198020002020NOAA NCEI Climate at a Glance

Illinois climate and rankings

Month pages

The weather in West Frankfort in each month, day by day.

What this means

A normal is the average of the thirty years 1991 to 2020, the period the World Meteorological Organization and NOAA use for comparison. It is an average, not a forecast: most days depart from it, and some by a long way.

A record is the highest or lowest value on the date in every year the station has reported, back to 1894. It rests on one station, so a neighbor a few miles away can hold different ones.

Cloud, humidity, wind and sunshine come from a reanalysis: a weather model run over the past with every observation fed in, averaged over a grid cell about 50 km across. It is consistent everywhere on Earth; it smooths local detail such as a lake shore or a valley.

More for this place

Nearby

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00117187 (Rend Lake Dam), public domain. Records: NOAA GHCN-Daily, station USC00111265, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus. Rankings: NOAA NCEI Climate at a Glance, public domain.