Monroe County climate

Monroe County Weather in September

NOAA 1991-2020 normals for Hannibal Locks & Dam, 19.7 km from Monroe County

Average highs run from 81°F on September 1 to 72°F on September 30, and lows from 59°F to 49°F. Normal precipitation for the month is 3.70 in over about 8 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 Monroe County, in °F, with the record for each date.20406080100151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
77°F
Average low
54°F
Precipitation
3.70 in
Record high
96°FSep 2, 1973
Record low
32°FSep 24, 1974
Chance of a freeze
1%
Days of 90°F or more
1.2
Daylight
13 h 03 min to 11 h 48 min
Cloud cover
55%
Humidity
67%
Dew point
54°F
Wind
3.6 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 181°F59°F95°F 197339°F 196727%0%
Sep 281°F58°F96°F 197339°F 196727%0%
Sep 381°F58°F96°F 201142°F 196727%0%
Sep 481°F58°F93°F 197342°F 199727%0%
Sep 580°F58°F92°F 200742°F 201027%0%
Sep 680°F57°F95°F 199840°F 198427%0%
Sep 780°F57°F94°F 200242°F 197627%0%
Sep 880°F57°F95°F 200239°F 198627%0%
Sep 979°F57°F95°F 196439°F 198627%0%
Sep 1079°F56°F96°F 198340°F 197227%0%
Sep 1179°F56°F94°F 198337°F 196927%0%
Sep 1278°F56°F92°F 201938°F 196727%0%
Sep 1378°F55°F92°F 201939°F 196427%0%
Sep 1478°F55°F92°F 201933°F 196427%0%
Sep 1577°F55°F92°F 199135°F 197527%0%
Sep 1677°F55°F93°F 199133°F 196627%0%
Sep 1777°F54°F90°F 199136°F 196627%0%
Sep 1876°F54°F90°F 196539°F 198427%0%
Sep 1976°F54°F90°F 196538°F 202027%0%
Sep 2076°F53°F91°F 197835°F 200027%0%
Sep 2175°F53°F90°F 197033°F 199127%0%
Sep 2275°F52°F91°F 197036°F 199128%0%
Sep 2375°F52°F92°F 197033°F 197428%0%
Sep 2474°F52°F91°F 197032°F 197428%0%
Sep 2574°F51°F91°F 200732°F 198328%0%
Sep 2673°F51°F89°F 201736°F 196528%0%
Sep 2773°F51°F91°F 201732°F 199129%0%
Sep 2873°F50°F86°F 197133°F 198929%0%
Sep 2972°F50°F88°F 197135°F 196929%0%
Sep 3072°F49°F87°F 198635°F 199229%0%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Monroe County, in percent, and of at least 0.1 inch of snowfall.01020301102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (EDT).

September 1
sunrise 6:52 AM, sunset 7:55 PM
September 30
sunrise 7:20 AM, sunset 7:08 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00333500 (Hannibal Locks & Dam), public domain. Records: NOAA GHCN-Daily, station USC00331197, 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.