Mercer Weather in September
Average highs run from 73°F on September 1 to 61°F on September 30, and lows from 50°F to 39°F. Normal precipitation for the month is 3.66 in over about 11 wet days.
September day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
September at a glance
- Average high
- 67°F
- Average low
- 45°F
- Precipitation
- 3.66 in
- Snowfall
- 0.1 in
- Record high
- 96°FSep 14, 1931
- Record low
- 16°FSep 25, 1997
- Chance of a freeze
- 74%
- Daylight
- 13 h 18 min to 11 h 44 min
- Cloud cover
- 62%
- Humidity
- 77%
- Dew point
- 49°F
- Wind
- 8.9 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.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Sep 1 | 73°F | 50°F | 91°F 1913 | 32°F 1994 | 34% | 0% |
| Sep 2 | 72°F | 50°F | 89°F 1953 | 30°F 1946 | 34% | 0% |
| Sep 3 | 72°F | 50°F | 95°F 1925 | 30°F 1946 | 34% | 0% |
| Sep 4 | 72°F | 50°F | 94°F 1925 | 30°F 1951 | 34% | 0% |
| Sep 5 | 71°F | 49°F | 90°F 1947 | 33°F 1957 | 35% | 0% |
| Sep 6 | 71°F | 49°F | 90°F 1936 | 28°F 1988 | 35% | 0% |
| Sep 7 | 71°F | 49°F | 92°F 1976 | 29°F 2009 | 35% | 0% |
| Sep 8 | 70°F | 48°F | 90°F 1976 | 27°F 1995 | 35% | 0% |
| Sep 9 | 70°F | 48°F | 93°F 1947 | 29°F 1995 | 35% | 0% |
| Sep 10 | 70°F | 48°F | 89°F 1931 | 25°F 1917 | 36% | 0% |
| Sep 11 | 69°F | 47°F | 93°F 1931 | 28°F 1917 | 36% | 0% |
| Sep 12 | 69°F | 47°F | 91°F 2005 | 28°F 1955 | 36% | 0% |
| Sep 13 | 68°F | 46°F | 91°F 1939 | 29°F 1953 | 36% | 0% |
| Sep 14 | 68°F | 46°F | 96°F 1931 | 25°F 1923 | 37% | 0% |
| Sep 15 | 68°F | 46°F | 91°F 1939 | 26°F 2007 | 37% | 0% |
| Sep 16 | 67°F | 45°F | 89°F 1948 | 23°F 1916 | 37% | 0% |
| Sep 17 | 67°F | 45°F | 91°F 1948 | 26°F 1959 | 37% | 0% |
| Sep 18 | 66°F | 44°F | 85°F 1955 | 26°F 2011 | 37% | 0% |
| Sep 19 | 66°F | 44°F | 84°F 1998 | 28°F 2012 | 38% | 0% |
| Sep 20 | 65°F | 43°F | 85°F 1919 | 24°F 1999 | 38% | 0% |
| Sep 21 | 65°F | 43°F | 85°F 1941 | 26°F 1997 | 38% | 0% |
| Sep 22 | 65°F | 43°F | 86°F 1941 | 23°F 1995 | 38% | 0% |
| Sep 23 | 64°F | 42°F | 83°F 2004 | 20°F 1927 | 38% | 1% |
| Sep 24 | 64°F | 42°F | 85°F 1935 | 24°F 1926 | 38% | 1% |
| Sep 25 | 63°F | 41°F | 86°F 1920 | 16°F 1997 | 39% | 1% |
| Sep 26 | 63°F | 41°F | 82°F 1938 | 21°F 1991 | 39% | 1% |
| Sep 27 | 62°F | 40°F | 86°F 1923 | 21°F 1991 | 39% | 1% |
| Sep 28 | 62°F | 40°F | 82°F 1948 | 20°F 1942 | 39% | 1% |
| Sep 29 | 61°F | 39°F | 85°F 1922 | 21°F 1945 | 39% | 1% |
| Sep 30 | 61°F | 39°F | 83°F 1948 | 22°F 1918 | 39% | 1% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- September 1
- sunrise 6:21 AM, sunset 7:39 PM
- September 30
- sunrise 6:58 AM, sunset 6:42 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00477092 (Rest Lake), public domain. Records: NOAA GHCN-Daily, station USC00477092, 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.