Heron Lake Weather in September
Average highs run from 77°F on September 1 to 67°F on September 30, and lows from 54°F to 43°F. Normal precipitation for the month is 3.11 in over about 8 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
- 73°F
- Average low
- 49°F
- Precipitation
- 3.11 in
- Record high
- 100°FSep 6, 1976
- Record low
- 18°FSep 22, 1913
- Chance of a freeze
- 42%
- Days of 90°F or more
- 0.6
- Daylight
- 13 h 12 min to 11 h 46 min
- Cloud cover
- 51%
- Humidity
- 66%
- Dew point
- 49°F
- Wind
- 11.2 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 | 77°F | 54°F | 96°F 1913 | 34°F 1949 | 30% | 0% |
| Sep 2 | 76°F | 54°F | 93°F 2011 | 36°F 1908 | 30% | 0% |
| Sep 3 | 76°F | 53°F | 97°F 2023 | 30°F 1974 | 30% | 0% |
| Sep 4 | 76°F | 53°F | 97°F 1913 | 33°F 1914 | 29% | 0% |
| Sep 5 | 76°F | 53°F | 99°F 1913 | 34°F 1909 | 29% | 0% |
| Sep 6 | 76°F | 52°F | 100°F 1976 | 35°F 1956 | 29% | 0% |
| Sep 7 | 75°F | 52°F | 99°F 1978 | 34°F 1956 | 29% | 0% |
| Sep 8 | 75°F | 52°F | 96°F 1947 | 38°F 1986 | 29% | 0% |
| Sep 9 | 75°F | 51°F | 94°F 1947 | 34°F 1910 | 29% | 0% |
| Sep 10 | 75°F | 51°F | 97°F 1906 | 34°F 1948 | 29% | 0% |
| Sep 11 | 74°F | 51°F | 95°F 1948 | 33°F 1955 | 29% | 0% |
| Sep 12 | 74°F | 50°F | 96°F 1948 | 33°F 1940 | 29% | 0% |
| Sep 13 | 74°F | 50°F | 97°F 1939 | 31°F 2014 | 29% | |
| Sep 14 | 74°F | 50°F | 97°F 1939 | 32°F 1949 | 29% | |
| Sep 15 | 73°F | 49°F | 97°F 1955 | 28°F 1916 | 29% | |
| Sep 16 | 73°F | 49°F | 95°F 1955 | 23°F 1937 | 29% | |
| Sep 17 | 73°F | 49°F | 97°F 1955 | 25°F 1916 | 29% | |
| Sep 18 | 72°F | 48°F | 93°F 1955 | 28°F 1918 | 29% | |
| Sep 19 | 72°F | 48°F | 96°F 1948 | 28°F 1991 | 29% | |
| Sep 20 | 72°F | 47°F | 91°F 1908 | 23°F 1918 | 29% | |
| Sep 21 | 71°F | 47°F | 98°F 2022 | 30°F 1918 | 29% | |
| Sep 22 | 71°F | 47°F | 91°F 1937 | 18°F 1913 | 29% | |
| Sep 23 | 70°F | 46°F | 90°F 2017 | 26°F 2012 | 29% | |
| Sep 24 | 70°F | 46°F | 88°F 1938 | 28°F 1942 | 29% | |
| Sep 25 | 70°F | 45°F | 89°F 1956 | 29°F 1942 | 28% | |
| Sep 26 | 69°F | 45°F | 91°F 1956 | 22°F 1984 | 28% | |
| Sep 27 | 69°F | 44°F | 94°F 1956 | 24°F 1984 | 28% | |
| Sep 28 | 68°F | 44°F | 89°F 1956 | 21°F 1942 | 28% | |
| Sep 29 | 68°F | 44°F | 87°F 2021 | 22°F 1916 | 28% | |
| Sep 30 | 67°F | 43°F | 90°F 2025 | 25°F 1956 | 28% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- September 1
- sunrise 6:45 AM, sunset 7:57 PM
- September 30
- sunrise 7:18 AM, sunset 7:04 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00214453 (Lakefield 2NE), public domain. Records: NOAA GHCN-Daily, station USC00219033, 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.