Brown County climate

Brown County Weather in September

NOAA 1991-2020 normals for Ainsworth, 14.9 km from Brown County

Average highs run from 83°F on September 1 to 73°F on September 30, and lows from 57°F to 46°F. Normal precipitation for the month is 2.56 in over about 7 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 Brown County, in °F, with the record for each date.20406080100120151015202530
  • Normal low
  • Normal high
  • Record high
  • Record low

September at a glance

Average high
78°F
Average low
52°F
Precipitation
2.56 in
Record high
107°FSep 9, 1931
Record low
21°FSep 29, 1945
Chance of a freeze
23%
Days of 90°F or more
3.2
Daylight
13 h 09 min to 11 h 47 min
Cloud cover
47%
Humidity
56%
Dew point
46°F
Wind
11.6 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 183°F57°F100°F 191237°F 196524%0%
Sep 283°F57°F104°F 202339°F 191424%0%
Sep 382°F57°F103°F 196037°F 193424%0%
Sep 482°F56°F102°F 193138°F 193524%0%
Sep 582°F56°F100°F 191332°F 193524%0%
Sep 682°F56°F105°F 193132°F 192923%0%
Sep 781°F55°F102°F 193134°F 192923%0%
Sep 881°F55°F105°F 202237°F 192923%0%
Sep 981°F55°F107°F 193134°F 194323%0%
Sep 1081°F54°F102°F 193135°F 192223%0%
Sep 1180°F54°F100°F 190828°F 194023%0%
Sep 1280°F54°F100°F 190833°F 197523%0%
Sep 1380°F53°F99°F 193930°F 194923%0%
Sep 1479°F53°F98°F 193933°F 199323%0%
Sep 1579°F53°F100°F 195527°F 191623%0%
Sep 1679°F52°F97°F 191033°F 191823%0%
Sep 1778°F52°F98°F 191028°F 191823%0%
Sep 1878°F51°F99°F 194029°F 191823%
Sep 1978°F51°F97°F 190823°F 191823%
Sep 2077°F51°F97°F 193727°F 192723%
Sep 2177°F50°F96°F 193630°F 191323%
Sep 2276°F50°F95°F 190826°F 199523%
Sep 2376°F49°F96°F 193726°F 198923%
Sep 2475°F49°F93°F 195625°F 194223%
Sep 2575°F49°F93°F 195624°F 191223%
Sep 2675°F48°F97°F 195625°F 194223%
Sep 2774°F48°F97°F 195624°F 192423%
Sep 2874°F47°F95°F 202424°F 195123%
Sep 2973°F47°F94°F 191021°F 194523%
Sep 3073°F46°F96°F 194226°F 197423%

Chance of rain

The chance of at least 0.01 inch of precipitation on each date at Brown County, in percent, and of at least 0.1 inch of snowfall.05101520251102030
  • Chance of a wet day
  • Chance of snowfall

Sunrise and sunset

Times for 2026, local time (CDT).

September 1
sunrise 7:05 AM, sunset 8:14 PM
September 30
sunrise 7:36 AM, sunset 7:23 PM

Every day of September: sun and moon

Other months

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00250050 (Ainsworth), public domain. Records: NOAA GHCN-Daily, station USC00250050, 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.