Climate averages 1991–2020

Bloomington (Indiana), United States weather
in September.

A warm, moderately wet month: the 4th warmest and the driest of the year. Meets the pleasant-weather rule

Long-term climate patterns, not a forecast for a particular trip.

Average high 25.3°C Daytime mean, September
Average low 15.6°C Night-time mean, September
Rainfall 73 mm 8 days with ≥1 mm
Daylight 12 h Sunrise to sunset, per day
Every month in Bloomington · average highYear overview

September is a warm month in Bloomington (Indiana), United States: daytime highs average 25.3°C and nights cool to about 15.6°C. By daytime temperature it is the 4th warmest of the 12 months.

Expect about 73 mm of rain on roughly 8 days, which makes September a moderately wet month (the driest month of the year). Daylight, from sunrise to sunset, lasts about 12 h 29 min on an average September day.

The nearest other city in this atlas is Indianapolis (74 km away). In September its highs average 24.6°C, 0.8°C cooler than Bloomington (Indiana), United States, with 72 mm of rain.

Among the 498 cities listed in the United States, Bloomington (Indiana), United States ranks joint 300th of 498 for the warmest September highs and joint 235th of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; Bloomington (Indiana), United States is 1.6°C cooler than that mean.

From September to October, average highs fall by 6.8°C to 18.5°C, and monthly rainfall rises from 73 mm to 83 mm.

The annual picture

September in context

30-year average
Average highAverage low°C
Average daily high and low temperatures by month The same values are available in the monthly table below. Lines show mean daily maxima and minima, not a forecast interval. -10-505101520253035 JanFebMarAprMayJunJulAugSepOctNovDec

Monthly rainfall

Average total · mm
Average monthly rainfall totalsEach bar is a mean monthly total over 1991–2020. Full numbers are in the table. JanFebMarAprMayJunJulAugSepOctNovDec 1500

Averages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated

Every month, side by side

Bloomington (Indiana), United States climate table

1991–2020
Monthly climate averages for Bloomington (Indiana), United States, 1991–2020
MonthAverage highHigh / lowAverage lowRainfall mm/monthRain days ≥1 mm/dayDaylight hours/dayDay­light h/day
January 3.2°C-4.7°C-4.7°C879.59.810 h
February 5.7°C-3.3°C-3.3°C748.510.711 h
March 11.3°C1.4°C1.4°C10110.811.912 h
April 17.6°C7.3°C7.3°C12812.413.213 h
May 22.5°C13.0°C13.0°C13013.414.314 h
June 27.3°C17.9°C17.9°C11111.914.915 h
July 29.3°C19.9°C19.9°C8811.414.615 h
August 28.8°C19.3°C19.3°C798.913.714 h
September, selected 25.3°C15.6°C15.6°C737.912.512 h
October 18.5°C9.5°C9.5°C838.211.211 h
November 11.0°C3.2°C3.2°C928.910.110 h
December 5.2°C-1.9°C-1.9°C8610.19.59 h

Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.

Compare places

September in nearby cities

Distance from Bloomington

Read the numbers correctly

Climate, not a promise.

These patterns help compare months. They cannot tell you the weather on a specific day of your trip.

Sources, method and limits

How these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Bloomington) is explained once on the Bloomington (Indiana), United States year overview and on the Sources, method and limits page.