climatesince.com

Brown County, IL

: September 2026 so far averaged 74°F in Brown County, IL, the warmest 1 to 29 September in the county average since the data begin in 1951 (county average from NOAA gridded data, 1951 to 2026).

Last updated . This page normally updates every day; the latest update is late.

High
79.3°F
Warmest since 2025
21st warmest of 76
Low
50.4°F
Warmest since 2025
31st warmest of 76

No measurable precipitation in the county average of Brown County, IL for 2 days to Tuesday 29 September 2026 (county average from NOAA gridded data, 1951 to 2026).

Every 29 September high of the county average in Brown County, IL since 1951: 79.3°F in 2026; the highest is 99°F, in 1953.
2025: 88.7°F1953: 99°F2026: 79.3°F 2026 79.3°F 1953 99°F since 2025 1951 2026
  • Normal range, 62.3 to 81.4°F
Every year as a table

Every 29 September low of the county average in Brown County, IL since 1951: 50.4°F in 2026; the lowest is 33.5°F, in 1984.

YearHigh, °FLow, °F
202679.350.4
202588.755.2
202476.860.7
20237755.7
202262.739.3
202187.558.6
202065.245.4
201979.963.8
20186847.3
201774.546.8
201662.251.4
201581.160
201484.256.1
201379.149.8
201270.244.1
20117251.6
201074.948.2
200964.346.4
200878.456.2
200781.749.6
20066342.3
200571.541.3
200471.440.2
200359.535.8
200281.453.2
200166.343.9
200073.447.4
19995947.6
199882.362.4
199775.252.4
199668.443.9
19957951
199471.545.3
199366.839.1
199262.337.9
199175.248.5
199077.457.2
198974.940.8
198883.159.3
198781.356.5
198688.167.7
198573.947.9
198455.633.5
198384.454.2
198279.355.7
198170.545.5
198075.344.4
197986.155.5
197869.743.8
19777348.8
197666.849.2
197569.348.5
197468.943.2
197379.662.3
19727746
197188.966.3
197073.644.3
196978.250.5
196875.450.2
196757.735.1
196669.250.3
196577.651.9
196468.638.7
196378.546.3
196270.836.8
196168.139.7
196074.348
195972.649.6
195870.442.4
195770.835.7
195686.154.8
195582.158.6
195483.864.1
19539965
195289.155.1
195161.935.5

The month

August 2026 averaged 74.7°F in Brown County, IL, the warmest August in the county average since 2021, tied 53rd warmest of 132 (with 2021) (county average from NOAA's monthly county data, 1895 to 2026).

The month in words
  • Tuesday 29 September 2026: a high of 79.3°F averaged over Brown County, IL, the warmest 29 September in the county average since 2025, tied 21st warmest of 76 (with 1982) (county average from NOAA gridded data, 1951 to 2026).
  • Tuesday 29 September 2026: a low of 50.4°F averaged over Brown County, IL, the warmest 29 September night in the county average since 2025, 31st warmest of 76 (county average from NOAA gridded data, 1951 to 2026).
Days of the month without a value
0

Nearby

Quincy, IL 23.7 mi, the nearest city with its own station