Park Forest, Illinois climate: Normal weather by month, frost dates and records
Park Forest's normal year runs from 15°F January nights to 84°F July afternoons, with 42.1 inches of precipitation and 28 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.9°C, January lows of −9°C, July highs of 29°C, 1,069 mm of precipitation a year.
- NOAA stationPark Forest
- Station IDUSC00116616
- Location41.49°N 87.68°W
- Elevation710 ft (216 m)
- From the centerunder 1 mile
- Population21,016
On October 22, the normal high in Park Forest is 60°F and the normal low 40°F, and the chance of measurable rain or snow is 34%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Park Forest.
- Jan 31° 15°
- Feb 35° 18°
- Mar 46° 28°
- Apr 59° 38°
- May 71° 49°
- Jun 80° 59°
- Jul 84° 64°
- Aug 82° 62°
- Sep 76° 55°
- Oct 63° 42°
- Nov 48° 31°
- Dec 36° 22°
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 Park Forest each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 15°F. The most precipitation falls in June (4.91 in), the least in February (2.15 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 31°F | 15°F | 23.2°F | 2.49 | 10.2 | 11 | <1 | 29 | 9 h 30 min |
| February | 35°F | 18°F | 26.8°F | 2.15 | 7.5 | 9 | <1 | 25 | 10 h 40 min |
| March | 46°F | 28°F | 37.2°F | 2.65 | 4.9 | 10 | <1 | 21 | 11 h 50 min |
| April | 59°F | 38°F | 48.8°F | 4.02 | 0.5 | 12 | <1 | 6 | 13 h 20 min |
| May | 71°F | 49°F | 60.0°F | 4.57 | 0.0 | 13 | 1 | <1 | 14 h 30 min |
| June | 80°F | 59°F | 69.5°F | 4.91 | 0.0 | 10 | 4 | <1 | 15 h 10 min |
| July | 84°F | 64°F | 73.9°F | 4.73 | 0.0 | 9 | 6 | <1 | 14 h 50 min |
| August | 82°F | 62°F | 72.0°F | 4.02 | 0.0 | 9 | 3 | <1 | 13 h 50 min |
| September | 76°F | 55°F | 65.2°F | 3.44 | 0.0 | 8 | 2 | <1 | 12 h 30 min |
| October | 63°F | 42°F | 52.8°F | 3.65 | 0.2 | 11 | <1 | 3 | 11 h 10 min |
| November | 48°F | 31°F | 39.8°F | 3.00 | 0.9 | 10 | <1 | 15 | 9 h 50 min |
| December | 36°F | 22°F | 28.9°F | 2.47 | 4.0 | 11 | <1 | 27 | 9 h 10 min |
| Year (annual) | 59°F | 40°F | 49.8°F | 42.10 | 28.2 | 124 | 16 | 126 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −9°C | −4.9°C | 63 mm | 26 cm |
| February | 2°C | −8°C | −2.9°C | 55 mm | 19 cm |
| March | 8°C | −2°C | 2.9°C | 67 mm | 12 cm |
| April | 15°C | 3°C | 9.3°C | 102 mm | 1 cm |
| May | 21°C | 10°C | 15.6°C | 116 mm | 0 cm |
| June | 27°C | 15°C | 20.8°C | 125 mm | 0 cm |
| July | 29°C | 18°C | 23.3°C | 120 mm | 0 cm |
| August | 28°C | 17°C | 22.2°C | 102 mm | 0 cm |
| September | 24°C | 13°C | 18.4°C | 87 mm | 0 cm |
| October | 17°C | 6°C | 11.6°C | 93 mm | 1 cm |
| November | 9°C | 0°C | 4.3°C | 76 mm | 2 cm |
| December | 2°C | −6°C | −1.7°C | 63 mm | 10 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00116616; 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 Park Forest?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September 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 USC00116616.
When is the last frost in Park Forest?
In Park Forest, the last spring frost (32°F) comes after April 23 in half of years and after May 11 in one year in ten; the first autumn frost comes before October 20 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 231 year in 10 after May 11; 9 in 10 after April 9
- First autumn frost, half of years before
- October 201 year in 10 before October 6; 9 in 10 before November 1
NOAA puts the median frost-free season at 179 days, and the season without a hard freeze (28°F) at 202 days.
A hard freeze (28°F) comes after April 12 in half of springs and before October 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Park Forest in zone 6a in ZIP code 60466. By the map's own method, the average of each year's coldest night over 1991-2020, Park Forest's NOAA station is in zone 6a: the coldest night of a typical year reaches −8°F (26 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 USC00116616; 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 Park Forest?
In a normal year in Park Forest, 16 days a year reach 90°F, 126 nights fall to 32°F or colder and 124 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
- 126a normal year
- Days that stay below freezing
- 46high of 32°F or less
- Days with 0.01 inch of precipitation
- 124a normal year
- Days with 1 inch of snow or more
- 13a normal year
The highest temperature in this station's record (since 1952) is 103°F, on August 2, 1988; the lowest is −27°F, on January 20, 1985.
The wettest calendar year on that record is 2006, with 54.55 in; the snowiest season is 1978–79, with 57.6 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00116616; records: ACIS (NOAA Regional Climate Centers), station USC00116616. Records use complete months only; a month missing more than three days is left out.
How sunny is Park Forest?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Park Forest, 3.8 kWh per square metre a day. July is the sunniest month (80%) and January the cloudiest (59%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 59% | 1.6 |
| February | 63% | 2.5 |
| March | 67% | 3.6 |
| April | 69% | 4.7 |
| May | 70% | 5.4 |
| June | 77% | 6.1 |
| July | 80% | 6.2 |
| August | 79% | 5.3 |
| September | 79% | 4.4 |
| October | 70% | 2.9 |
| November | 66% | 1.9 |
| December | 59% | 1.4 |
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 Park Forest need?
A normal year in Park Forest brings 6,350 heating degree days, 18% more than the median U.S. place (5,373), and 859 cooling degree days, 5% 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 3,114 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,297 | 0 |
| February | 1,070 | 0 |
| March | 862 | 2 |
| April | 493 | 7 |
| May | 215 | 58 |
| June | 40 | 177 |
| July | 4 | 279 |
| August | 9 | 226 |
| September | 93 | 99 |
| October | 392 | 12 |
| November | 756 | 0 |
| December | 1,119 | 0 |
| Year (annual) | 6,350 | 859 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00116616. 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 Park Forest been warmer than normal lately?
2025 averaged 50.9°F, 1.1°F above the 1991-2020 normal of 49.8°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 51.5°F | +1.7°F | 41.12 | 40.6 |
| 2022 | 49.4°F | −0.4°F | 34.65 | 28.5 |
| 2023 | 51.9°F | +2.1°F | 44.40 | 6.6 |
| 2024 | 53.2°F | +3.4°F | 41.65 | 11.2 |
| 2025 | 50.9°F | +1.1°F | 31.39 | 22.6 |
Over 57 complete years from 1954 to 2025, the station's annual mean temperature rose at a fitted 3.0°F per century (+0.17°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00116616; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Park Forest's climate compare?
Park Forest is warmer than 34 of the other 143 places with their own NOAA record in Illinois, and wetter than 103. Across the 7,247 U.S. stations with normals, its annual mean of 49.8°F is warmer than 39%.
In the Köppen classification computed from these normals, Park Forest 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 Park Forest share this climate record?
48 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.
- Hammond, INalso near: Burbank (17 mi, 52.4°F a year); Chicago Midway Airport (18 mi, 52.1°F a year)76,030 people · 13 mi NE
- Gary, INalso near: Indiana Dunes National Lakeshore (14 mi, 50.2°F a year); Valparaiso Water Works (17 mi, 50.5°F a year)67,555 people · 18 mi E
- Tinley Park, ILalso near: Little Red School House (10 mi, 51.4°F a year); Burbank (12 mi, 52.4°F a year)54,856 people · 8 mi NW
- Merrillville, IN36,989 people · 19 mi E
- Crown Point, IN35,097 people · 18 mi E
- Calumet City, IL34,855 people · 10 mi NE
- Schererville, IN29,780 people · 12 mi E
- Hobart, IN29,418 people · 21 mi E
- Lansing, IL28,107 people · 8 mi NE
- Oak Forest, IL26,813 people · 9 mi NW
- Chicago Heights, IL26,533 people · 3 mi NE
- East Chicago, IN25,768 people · 16 mi NE
- St. John, IN24,250 people · 12 mi E
- Munster, IN23,634 people · 10 mi E
- Highland, IN23,497 people · 12 mi E
- Frankfort, IL21,160 people · 10 mi W
- South Holland, IL20,775 people · 8 mi NE
- Dolton, IL20,697 people · 10 mi NE
- Mokena, IL19,915 people · 11 mi W
- Harvey, IL19,781 people · 8 mi N
- Homewood, IL18,789 people · 5 mi N
- Matteson, IL18,566 people · 4 mi W
- Cedar Lake, IN16,404 people · 15 mi SE
- Dyer, IN16,341 people · 9 mi E
- Country Club Hills, IL16,238 people · 5 mi NW
- Griffith, IN16,192 people · 13 mi E
- Hazel Crest, IL13,036 people · 6 mi N
- Richton Park, IL12,504 people · 3 mi W
- Markham, IL11,290 people · 7 mi N
- Frankfort Square, IL9,777 people · 7 mi W
- Sauk Village, IL9,627 people · 6 mi E
- Steger, IL9,376 people · 4 mi SE
- Flossmoor, IL9,371 people · 3 mi N
- Lynwood, IL9,239 people · 7 mi E
- Glenwood, IL8,413 people · 5 mi NE
- Crete, IL8,371 people · 5 mi SE
- University Park, IL7,043 people · 4 mi SW
- Ross, IN6,740 people · 16 mi E
- Monee, IL5,139 people · 6 mi SW
- Olympia Fields, IL4,593 people · 2 mi N
- Burnham, IL3,916 people · 12 mi NE
- South Chicago Heights, IL3,887 people · 2 mi E
- Thornton, IL2,300 people · 6 mi NE
- Ford Heights, IL1,752 people · 5 mi E
- Phoenix, IL1,650 people · 9 mi N
- Arbury Hills, IL1,408 people · 9 mi W
- East Hazel Crest, IL1,254 people · 6 mi N
- Andres, IL42 people · 13 mi SW
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 Park Forest's climate
What is the coldest month in Park Forest?
January, with a normal high of 31°F and a normal low of 15°F. The warmest is July (84°F by day, 64°F at night).
Does it snow in Park Forest?
Yes: 28 inches in a normal year, falling on 18 days with 0.1 inch or more, the most in January (10.2 inches).
What is the rainiest month in Park Forest?
June, with 4.91 in of precipitation in a normal year; the driest is February with 2.15 in.
What plant hardiness zone is Park Forest in?
The USDA's 2023 map puts Park Forest in zone 6a in ZIP code 60466. By the same method at Park Forest's NOAA station, the coldest night of a typical year reaches −8°F (26 years, 1991-2020): zone 6a.
How late can frost come in Park Forest?
In half of years the last 32°F night comes after April 23; in one year in ten it comes after May 11. Waiting until May 11 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Burbank, IL17 miles from this station, 52.4°F a year
- Little Red School House, IL18 miles from this station, 51.4°F a year
- Chicago Midway Airport, IL21 miles from this station, 52.1°F a year
- Lowell, IN21 miles from this station, 49.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made