Mundelein, Illinois climate: Normal weather by month, frost dates and records
Mundelein's normal year runs from 14°F January nights to 82°F July afternoons, with 38.5 inches of precipitation and 43 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.8°C, January lows of −10°C, July highs of 28°C, 977 mm of precipitation a year.
- NOAA stationMundelein (4 mi WSW)
- Station IDUSC00115961
- Location42.26°N 88.08°W
- Elevation840 ft (256 m)
- From the center3 miles
- Population32,641
On October 23, the normal high in Mundelein is 58°F and the normal low 39°F, and the chance of measurable rain or snow is 33%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Mundelein.
- Jan 29° 14°
- Feb 33° 16°
- Mar 44° 26°
- Apr 57° 36°
- May 68° 47°
- Jun 78° 58°
- Jul 82° 62°
- Aug 81° 61°
- Sep 74° 53°
- Oct 61° 42°
- Nov 47° 30°
- Dec 34° 20°
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 Mundelein each month?
July is the warmest month, with normal highs of 82°F; January the coldest, with normal lows of 14°F. The most precipitation falls in May (4.57 in), the least in January (1.76 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. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 29°F | 14°F | 21.2°F | 1.76 | 11.0 | 10 | <1 | 29 | 9 h 20 min |
| February | 33°F | 16°F | 24.6°F | 1.93 | 12.8 | 10 | <1 | 27 | 10 h 30 min |
| March | 44°F | 26°F | 35.0°F | 2.49 | 5.3 | 11 | <1 | 23 | 11 h 50 min |
| April | 57°F | 36°F | 46.3°F | 3.95 | 1.8 | 12 | <1 | 10 | 13 h 20 min |
| May | 68°F | 47°F | 57.7°F | 4.57 | 0.0 | 14 | <1 | 1 | 14 h 30 min |
| June | 78°F | 58°F | 67.8°F | 4.38 | 0.0 | 12 | 2 | <1 | 15 h 10 min |
| July | 82°F | 62°F | 72.2°F | 4.01 | 0.0 | 10 | 5 | <1 | 15 h |
| August | 81°F | 61°F | 70.8°F | 4.19 | 0.0 | 10 | 3 | <1 | 14 h |
| September | 74°F | 53°F | 63.3°F | 3.38 | 0.0 | 9 | 1 | <1 | 12 h 30 min |
| October | 61°F | 42°F | 51.1°F | 3.20 | 0.0 | 11 | <1 | 5 | 11 h 10 min |
| November | 47°F | 30°F | 38.3°F | 2.47 | 2.5 | 10 | <1 | 18 | 9 h 50 min |
| December | 34°F | 20°F | 26.9°F | 2.12 | 9.7 | 11 | <1 | 28 | 9 h 10 min |
| Year (annual) | 57°F | 39°F | 47.9°F | 38.45 | 43.1 | 128 | 11 | 140 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −2°C | −10°C | −6.0°C | 45 mm | 28 cm |
| February | 0°C | −9°C | −4.1°C | 49 mm | 33 cm |
| March | 7°C | −3°C | 1.7°C | 63 mm | 13 cm |
| April | 14°C | 2°C | 7.9°C | 100 mm | 5 cm |
| May | 20°C | 9°C | 14.3°C | 116 mm | 0 cm |
| June | 26°C | 14°C | 19.9°C | 111 mm | 0 cm |
| July | 28°C | 17°C | 22.3°C | 102 mm | 0 cm |
| August | 27°C | 16°C | 21.6°C | 106 mm | 0 cm |
| September | 23°C | 12°C | 17.4°C | 86 mm | 0 cm |
| October | 16°C | 5°C | 10.6°C | 81 mm | 0 cm |
| November | 8°C | −1°C | 3.5°C | 63 mm | 6 cm |
| December | 1°C | −7°C | −2.8°C | 54 mm | 25 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00115961; 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 Mundelein?
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 (9).
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 USC00115961.
When is the last frost in Mundelein?
In Mundelein, the last spring frost (32°F) comes after April 29 in half of years and after May 15 in one year in ten; the first autumn frost comes before October 20 in half of years and before October 4 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 291 year in 10 after May 15; 9 in 10 after April 14
- First autumn frost, half of years before
- October 201 year in 10 before October 4; 9 in 10 before November 1
NOAA puts the median frost-free season at 172 days, and the season without a hard freeze (28°F) at 196 days.
A hard freeze (28°F) comes after April 16 in half of springs and before October 31 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Mundelein in zone 5b in ZIP code 60060. By the map's own method, the average of each year's coldest night over 1991-2020, Mundelein's NOAA station is in zone 5b: the coldest night of a typical year reaches −11°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 USC00115961; 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 Mundelein?
In a normal year in Mundelein, 11 days a year reach 90°F, 140 nights fall to 32°F or colder and 128 days bring measurable precipitation.
- Days at 90°F or more
- 11a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 140a normal year
- Days that stay below freezing
- 54high of 32°F or less
- Days with 0.01 inch of precipitation
- 128a normal year
- Days with 1 inch of snow or more
- 13a normal year
The highest temperature in this station's record (since 1999) is 103°F, on July 7, 2012; the lowest is −26°F, on January 31, 2019.
The wettest calendar year on that record is 2019, with 54.17 in; the snowiest season is 2007–08, with 78.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00115961; records: ACIS (NOAA Regional Climate Centers), station USC00115961. Records use complete months only; a month missing more than three days is left out.
How sunny is Mundelein?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Mundelein, 3.9 kWh per square metre a day. July is the sunniest month (80%) and December the cloudiest (61%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 63% | 1.7 |
| February | 67% | 2.6 |
| March | 67% | 3.6 |
| April | 69% | 4.7 |
| May | 70% | 5.5 |
| June | 76% | 6.1 |
| July | 80% | 6.3 |
| August | 79% | 5.4 |
| September | 78% | 4.3 |
| October | 69% | 2.8 |
| November | 66% | 1.9 |
| December | 61% | 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 Mundelein need?
A normal year in Mundelein brings 6,875 heating degree days, 28% more than the median U.S. place (5,373), and 693 cooling degree days, 24% 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 2,783 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,358 | 0 |
| February | 1,131 | 0 |
| March | 931 | 1 |
| April | 566 | 4 |
| May | 265 | 39 |
| June | 55 | 141 |
| July | 11 | 234 |
| August | 13 | 193 |
| September | 126 | 74 |
| October | 437 | 8 |
| November | 800 | 0 |
| December | 1,181 | 0 |
| Year (annual) | 6,875 | 693 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00115961. 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 Mundelein been warmer than normal lately?
2023 averaged 50.0°F, 2.1°F above the 1991-2020 normal of 47.9°F. 2 of the 3 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 49.5°F | +1.6°F | 28.48 | 38.7 |
| 2022 | 47.3°F | −0.6°F | 36.97 | 30.6 |
| 2023 | 50.0°F | +2.1°F | 36.81 | 28.5 |
Source: observed years: ACIS, station USC00115961. A year counts only with all twelve months complete.
How does Mundelein's climate compare?
Mundelein is warmer than 6 of the other 143 places with their own NOAA record in Illinois, and wetter than 43. Across the 7,247 U.S. stations with normals, its annual mean of 47.9°F is warmer than 31%.
In the Köppen classification computed from these normals, Mundelein 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 Mundelein share this climate record?
16 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.
- Vernon Hills, IL27,002 people · 6 mi E
- Grayslake, IL21,262 people · 6 mi N
- Libertyville, IL20,643 people · 6 mi E
- Lake Zurich, IL19,960 people · 4 mi S
- Round Lake, IL18,654 people · 6 mi N
- Wauconda, IL14,055 people · 3 mi NW
- Hawthorn Woods, IL9,584 people · 1 mi S
- Long Grove, IL8,393 people · 5 mi SE
- Round Lake Park, IL7,836 people · 6 mi N
- Lake Barrington, IL5,160 people · 6 mi SW
- Kildeer, IL4,554 people · 5 mi S
- Hainesville, IL3,532 people · 6 mi N
- North Barrington, IL3,142 people · 4 mi SW
- Forest Lake, IL1,797 people · 3 mi SE
- Tower Lakes, IL1,213 people · 4 mi SW
- Indian Creek, IL535 people · 5 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 Mundelein's climate
What is the coldest month in Mundelein?
January, with a normal high of 29°F and a normal low of 14°F. The warmest is July (82°F by day, 62°F at night).
Does it snow in Mundelein?
Yes: 43 inches in a normal year, falling on 31 days with 0.1 inch or more, the most in February (12.8 inches).
What is the rainiest month in Mundelein?
May, with 4.57 in of precipitation in a normal year; the driest is January with 1.76 in.
What plant hardiness zone is Mundelein in?
The USDA's 2023 map puts Mundelein in zone 5b in ZIP code 60060. By the same method at Mundelein's NOAA station, the coldest night of a typical year reaches −11°F (21 years, 1991-2020): zone 5b.
How late can frost come in Mundelein?
In half of years the last 32°F night comes after April 29; in one year in ten it comes after May 15. Waiting until May 15 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Mundelein in OctoberThis month day by day, its records and recent years
- Illinois climateThe statewide normals and every place in the state
- McHenry W.G. Stratton Lock and Dam, IL10 miles from this station, 48.6°F a year
- Barrington, IL11 miles from this station, 48.0°F a year
- Waukegan, IL12 miles from this station, 48.4°F a year
- Lake Villa, IL12 miles from this station, 48.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made