Knollwood climate

Knollwood Weather in September

NOAA 1991-2020 normals for Mundelein 4 Wsw, 16.1 km from Knollwood

Average highs run from 79°F on September 1 to 68°F on September 30, and lows from 58°F to 47°F. Normal precipitation for the month is 3.38 in over about 9 wet days.

September day by day

The normal high and low for each date, and the record, in °F.

Normal daily high and low temperature at Knollwood, in °F, with the record for each date.20406080100151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
74°F
Average low
53°F
Precipitation
3.38 in
Record high
96°FSep 10, 2013
Record low
34°FSep 19, 2012
Chance of a freeze
7%
Days of 90°F or more
1.0
Daylight
13 h 08 min to 11 h 47 min
Cloud cover
59%
Humidity
74%
Dew point
54°F
Wind
9.6 mph

Every day of the month

A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.

DateNormal highNormal lowRecord highRecord lowChance wetChance of snow
Sep 179°F58°F93°F 202643°F 200931%0%
Sep 278°F58°F93°F 202644°F 201731%0%
Sep 378°F58°F94°F 202349°F 200931%0%
Sep 478°F57°F91°F 202345°F 200931%0%
Sep 578°F57°F92°F 202345°F 200331%0%
Sep 677°F57°F93°F 201645°F 202531%0%
Sep 777°F56°F88°F 200145°F 202531%0%
Sep 877°F56°F84°F 200245°F 202431%0%
Sep 976°F55°F91°F 201345°F 200831%0%
Sep 1076°F55°F96°F 201343°F 200831%0%
Sep 1176°F55°F91°F 200544°F 201731%0%
Sep 1275°F54°F90°F 200542°F 201431%0%
Sep 1375°F54°F93°F 200539°F 201431%0%
Sep 1475°F54°F86°F 202140°F 201131%0%
Sep 1574°F53°F86°F 200435°F 201231%0%
Sep 1674°F53°F84°F 201641°F 200731%0%
Sep 1773°F52°F91°F 202142°F 201431%0%
Sep 1873°F52°F87°F 200740°F 201231%0%
Sep 1973°F52°F88°F 201634°F 201231%0%
Sep 2072°F51°F89°F 202440°F 200332%0%
Sep 2172°F51°F88°F 201037°F 200632%0%
Sep 2271°F50°F92°F 201740°F 199932%0%
Sep 2371°F50°F88°F 201036°F 201232%0%
Sep 2471°F49°F89°F 200735°F 201232%0%
Sep 2570°F49°F85°F 200738°F 200132%0%
Sep 2670°F49°F90°F 201740°F 200432%0%
Sep 2769°F48°F89°F 202541°F 201232%0%
Sep 2869°F48°F82°F 201339°F 200633%0%
Sep 2968°F48°F88°F 202535°F 201833%0%
Sep 3068°F47°F85°F 201935°F 200433%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Knollwood, in percent, and of at least 0.1 inch of snowfall.0102030401102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (CDT).

September 1
sunrise 6:17 AM, sunset 7:25 PM
September 30
sunrise 6:48 AM, sunset 6:35 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00115961 (Mundelein 4 Wsw), public domain. Records: NOAA GHCN-Daily, station USW00014880, 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.