Mundelein weather in September: Mundelein, Illinois: normal highs, lows, rain and records for September
Mundelein in September has a normal high of 74°F and a normal low of 53°F, a daily mean of 63°F, falling from 79°F on the 1st to 68°F by the 30th. Measurable precipitation falls on 9 days in a normal September, 3.38 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 23°C and low of 12°C, 86 mm of precipitation in September.
- NOAA stationMundelein (4 mi WSW)
- Station IDUSC00115961
- Location42.26°N 88.08°W
- Elevation840 ft (256 m)
- From the center3 miles
- Population32,641
- 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.
How warm is Mundelein in September?
The normal high is 74°F and the normal low 53°F, for a daily mean of 63.3°F. September is 7.5°F cooler than August and 12.2°F warmer than October. September is the 4th warmest month of the year in Mundelein and the 6th wettest. Across the month the normal high falls 11°F, from 79°F on September 1 to 68°F on September 30. From one year to the next September's mean temperature typically moves about 2.6°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 61°F and 66°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 33%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 79°F | 58°F | 31% | 19% |
| September 8 | 77°F | 56°F | 31% | 20% |
| September 15 | 74°F | 53°F | 31% | 20% |
| September 22 | 71°F | 50°F | 32% | 20% |
| September 30 | 68°F | 47°F | 33% | 20% |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 1, coldest night September 30)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 79°F | 58°F | 31% | 19% | 13 h 10 min |
| September 2 | 78°F | 58°F | 31% | 19% | 13 h 10 min |
| September 3 | 78°F | 58°F | 31% | 19% | 13 h 10 min |
| September 4 | 78°F | 57°F | 31% | 19% | 13 h |
| September 5 | 78°F | 57°F | 31% | 19% | 13 h |
| September 6 | 77°F | 57°F | 31% | 19% | 13 h |
| September 7 | 77°F | 56°F | 31% | 20% | 13 h |
| September 8 | 77°F | 56°F | 31% | 20% | 12 h 50 min |
| September 9 | 76°F | 55°F | 31% | 20% | 12 h 50 min |
| September 10 | 76°F | 55°F | 31% | 20% | 12 h 50 min |
| September 11 | 76°F | 55°F | 31% | 20% | 12 h 40 min |
| September 12 | 75°F | 54°F | 31% | 20% | 12 h 40 min |
| September 13 | 75°F | 54°F | 31% | 20% | 12 h 40 min |
| September 14 | 75°F | 54°F | 31% | 20% | 12 h 40 min |
| September 15 | 74°F | 53°F | 31% | 20% | 12 h 30 min |
| September 16 | 74°F | 53°F | 31% | 20% | 12 h 30 min |
| September 17 | 73°F | 52°F | 31% | 20% | 12 h 30 min |
| September 18 | 73°F | 52°F | 31% | 20% | 12 h 20 min |
| September 19 | 73°F | 52°F | 31% | 20% | 12 h 20 min |
| September 20 | 72°F | 51°F | 32% | 20% | 12 h 20 min |
| September 21 | 72°F | 51°F | 32% | 20% | 12 h 20 min |
| September 22 | 71°F | 50°F | 32% | 20% | 12 h 10 min |
| September 23 | 71°F | 50°F | 32% | 20% | 12 h 10 min |
| September 24 | 71°F | 49°F | 32% | 20% | 12 h 10 min |
| September 25 | 70°F | 49°F | 32% | 20% | 12 h 10 min |
| September 26 | 70°F | 49°F | 32% | 20% | 12 h |
| September 27 | 69°F | 48°F | 32% | 20% | 12 h |
| September 28 | 69°F | 48°F | 33% | 20% | 12 h |
| September 29 | 68°F | 48°F | 33% | 20% | 11 h 50 min |
| September 30 | 68°F | 47°F | 33% | 20% | 11 h 50 min |
- Normal high
- 74°FSeptember average
- Normal low
- 53°FSeptember average
- Precipitation
- 3.38 inmonth total
- Days with precipitation
- 90.01 inch or more
- Days at 90°F or more
- 1
- Daylight
- 13 h 10 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 21
- Days at 80°F or more
- 9
- Sunshine
- 78%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00115961; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Mundelein in September?
On a given September day the chance of 0.01 inch or more is 31% on average, highest around September 30 (33%). In all, 3.38 in falls on 9 days of a normal September, 1 of them with an inch or more.
In a normal September in Mundelein, 1 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00115961.
What are the records for September in Mundelein?
The warmest September temperature on this station's record (since 1999) is 94°F, on September 2, 2000; the coldest is 34°F, on September 24, 2012. The wettest September brought 10.62 in (2019).
The September mean against the 1991-2020 normal of 63.3°F: 2021 65.9°F (+2.6), 2022 64.0°F (+0.7), 2023 65.0°F (+1.7). 3 of 3 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 65.9°F | +2.6°F | 1.94 in |
| 2022 | 64.0°F | +0.7°F | 4.36 in |
| 2023 | 65.0°F | +1.7°F | 4.84 in |
Source: records: ACIS, station USC00115961; recent months: ACIS, station USC00115961. Records and recent months use complete months only.
How does September in Mundelein compare across Illinois?
Across the 144 places PlainClimate covers in Illinois, September normal highs run from 72°F in Barrington to 84°F in Anna; Mundelein's is 74°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.