Pontiac, Illinois climate: Normal weather by month, frost dates and records
Pontiac's normal year runs from 17°F January nights to 84°F July afternoons, with 37.0 inches of precipitation and 25 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.0°C, January lows of −8°C, July highs of 29°C, 939 mm of precipitation a year.
- NOAA stationPontiac
- Station IDUSC00116910
- Location40.88°N 88.64°W
- Elevation650 ft (198 m)
- From the centerunder 1 mile
- Population11,054
On October 23, the normal high in Pontiac is 62°F and the normal low 41°F, and the chance of measurable rain or snow is 28%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Pontiac.
- Jan 32° 17°
- Feb 37° 21°
- Mar 49° 30°
- Apr 63° 41°
- May 74° 52°
- Jun 82° 62°
- Jul 84° 66°
- Aug 83° 64°
- Sep 78° 56°
- Oct 65° 44°
- Nov 50° 33°
- Dec 38° 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 Pontiac each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 17°F. The most precipitation falls in May (4.43 in), the least in February (1.76 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 32°F | 17°F | 24.8°F | 1.99 | 6.7 | 9 | <1 | 28 | 9 h 30 min |
| February | 37°F | 21°F | 28.8°F | 1.76 | 8.0 | 8 | <1 | 25 | 10 h 40 min |
| March | 49°F | 30°F | 39.6°F | 2.62 | 3.4 | 10 | <1 | 20 | 11 h 50 min |
| April | 63°F | 41°F | 51.7°F | 3.49 | 0.6 | 11 | <1 | 6 | 13 h 20 min |
| May | 74°F | 52°F | 62.8°F | 4.43 | 0.0 | 12 | 1 | <1 | 14 h 30 min |
| June | 82°F | 62°F | 72.0°F | 3.90 | 0.0 | 10 | 5 | <1 | 15 h 10 min |
| July | 84°F | 66°F | 75.0°F | 3.71 | 0.0 | 9 | 5 | <1 | 14 h 50 min |
| August | 83°F | 64°F | 73.3°F | 3.73 | 0.0 | 9 | 4 | <1 | 13 h 50 min |
| September | 78°F | 56°F | 66.9°F | 3.39 | 0.0 | 8 | 2 | <1 | 12 h 30 min |
| October | 65°F | 44°F | 54.6°F | 3.24 | 0.0 | 8 | <1 | 3 | 11 h 10 min |
| November | 50°F | 33°F | 41.3°F | 2.56 | 0.7 | 9 | <1 | 15 | 10 h |
| December | 38°F | 23°F | 30.3°F | 2.13 | 5.7 | 9 | <1 | 26 | 9 h 20 min |
| Year (annual) | 61°F | 42°F | 51.8°F | 36.95 | 25.1 | 112 | 17 | 122 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −8°C | −4.0°C | 51 mm | 17 cm |
| February | 3°C | −6°C | −1.8°C | 45 mm | 20 cm |
| March | 10°C | −1°C | 4.2°C | 67 mm | 9 cm |
| April | 17°C | 5°C | 10.9°C | 89 mm | 2 cm |
| May | 23°C | 11°C | 17.1°C | 113 mm | 0 cm |
| June | 28°C | 17°C | 22.2°C | 99 mm | 0 cm |
| July | 29°C | 19°C | 23.9°C | 94 mm | 0 cm |
| August | 28°C | 18°C | 22.9°C | 95 mm | 0 cm |
| September | 26°C | 13°C | 19.4°C | 86 mm | 0 cm |
| October | 19°C | 7°C | 12.6°C | 82 mm | 0 cm |
| November | 10°C | 0°C | 5.2°C | 65 mm | 2 cm |
| December | 3°C | −5°C | −0.9°C | 54 mm | 14 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00116910; 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 Pontiac?
Normal highs sit between 65°F and 85°F in May, June, July, August, September and October. 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 USC00116910.
When is the last frost in Pontiac?
In Pontiac, the last spring frost (32°F) comes after April 16 in half of years and after May 2 in one year in ten; the first autumn frost comes before October 24 in half of years and before October 12 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 161 year in 10 after May 2; 9 in 10 after April 3
- First autumn frost, half of years before
- October 241 year in 10 before October 12; 9 in 10 before November 5
NOAA puts the median frost-free season at 191 days, and the season without a hard freeze (28°F) at 213 days.
A hard freeze (28°F) comes after April 4 in half of springs and before November 3 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Pontiac in zone 6a in ZIP code 61764, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Pontiac's NOAA station is in zone 6a: the coldest night of a typical year reaches −8°F (25 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 USC00116910; 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 Pontiac?
In a normal year in Pontiac, 17 days a year reach 90°F, 122 nights fall to 32°F or colder and 112 days bring measurable precipitation.
- Days at 90°F or more
- 17a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 122a normal year
- Days that stay below freezing
- 42high of 32°F or less
- Days with 0.01 inch of precipitation
- 112a normal year
- Days with 1 inch of snow or more
- 9a normal year
The highest temperature in this station's record (since 1903) is 108°F, on July 14, 1936; the lowest is −24°F, on January 15, 1927.
The wettest calendar year on that record is 2007, with 51.28 in; the snowiest season is 2010–11, with 52.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00116910; records: ACIS (NOAA Regional Climate Centers), station USC00116910. Records use complete months only; a month missing more than three days is left out.
How sunny is Pontiac?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Pontiac, 4.0 kWh per square metre a day. July is the sunniest month (82%) and December the cloudiest (62%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 64% | 1.9 |
| February | 67% | 2.7 |
| March | 67% | 3.7 |
| April | 71% | 4.8 |
| May | 72% | 5.5 |
| June | 79% | 6.3 |
| July | 82% | 6.3 |
| August | 81% | 5.5 |
| September | 81% | 4.6 |
| October | 72% | 3.1 |
| November | 69% | 2.1 |
| December | 62% | 1.6 |
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 Pontiac need?
A normal year in Pontiac brings 5,840 heating degree days, 9% more than the median U.S. place (5,373), and 1,052 cooling degree days, 16% 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 3,503 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,246 | 0 |
| February | 1,015 | 0 |
| March | 788 | 2 |
| April | 411 | 12 |
| May | 152 | 85 |
| June | 20 | 231 |
| July | 2 | 312 |
| August | 5 | 263 |
| September | 72 | 129 |
| October | 343 | 19 |
| November | 710 | 1 |
| December | 1,077 | 0 |
| Year (annual) | 5,840 | 1,052 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00116910. 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 Pontiac's climate compare?
Pontiac is warmer than 71 of the other 143 places with their own NOAA record in Illinois, and wetter than 13. Across the 7,247 U.S. stations with normals, its annual mean of 51.8°F is warmer than 49%.
In the Köppen classification computed from these normals, Pontiac 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 Pontiac share this climate record?
Saunemin has no NOAA station with 1991-2020 normals of its 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.
- Saunemin, IL406 people · 12 mi E
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 Pontiac's climate
What is the coldest month in Pontiac?
January, with a normal high of 32°F and a normal low of 17°F. The warmest is July (84°F by day, 66°F at night).
Does it snow in Pontiac?
Yes: 25 inches in a normal year, falling on 14 days with 0.1 inch or more, the most in February (8.0 inches).
What is the rainiest month in Pontiac?
May, with 4.43 in of precipitation in a normal year; the driest is February with 1.76 in.
What plant hardiness zone is Pontiac in?
The USDA's 2023 map puts Pontiac in zone 6a in ZIP code 61764, the nearest ZIP area. By the same method at Pontiac's NOAA station, the coldest night of a typical year reaches −8°F (25 years, 1991-2020): zone 6a.
How late can frost come in Pontiac?
In half of years the last 32°F night comes after April 16; in one year in ten it comes after May 2. Waiting until May 2 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Illinois climateThe statewide normals and every place in the state
- Chenoa, IL11 miles from this station, 50.5°F a year
- Streator, IL17 miles from this station, 51.6°F a year
- Dwight, IL20 miles from this station, 49.3°F a year
- Minonk, IL21 miles from this station, 51.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made