Springfield Weather in September (1981–2025)

📍 39.79°N, 89.65°W •
📊

September at a Glance in Springfield

(1981–2025)
Avg High
🔥
26.4°C
Avg Low
❄️
13.6°C
Avg Temp
🌡️
20.0°C
Avg Rain
🌧️
74 mm
Avg Humidity
💧
68%
Avg Wind
🌬️
2.5 m/s
Avg Solar
☀️
4.6
kWh/m²/day
vs Annual
📈
+8.6°C
temp difference
🌡️Warm afternoons🌤️Cool mornings🌤️Fairly sunny🌧️Wet month🍃Light winds😊Comfortable humidity

Springfield September Weather Overview

September is one of the warmer months of the year in Springfield, with average highs near 26.4°C and lows around 13.6°C (mean 20°C). It is about average for rainfall, averaging 74 mm of rainfall and 68% relative humidity across the period.

Springfield September Temperature History (1981–2025)

Range

September is one of the warmer months of the year in Springfield. Across 45 years of records, the warmest September in Springfield was 2019 — when the month averaged 23.2°C — while the coldest was 1993 at 15.8°C. Typical September days reach 26.4°C with nights near 13.6°C. The long-term trend is warming, about 0.5°C per decade.

1981–1985 vs 2021–2025

Avg Temp19.1°C→21.3°C+2.2°C
Max Temp25.3°C→28.0°C+2.7°C
Min Temp12.8°C→14.6°C+1.8°C

Trend (per decade)

Avg Temp+0.5°C/decade ↗
Max Temp+0.5°C/decade ↗
Min Temp+0.5°C/decade ↗

Distribution of Avg Temp

15.0°C–17.3°C2 yr (4%)
17.3°C–19.5°C17 yr (38%)
19.5°C–21.8°C21 yr (47%)
21.8°C–24.0°C5 yr (11%)

Springfield September Rainfall History (1981–2025)

Range

September is about average for rainfall in Springfield, averaging 74 mm of rainfall. The wettest September on record was 2008 with 249 mm, while the driest was 2004 at 14 mm.

Springfield September Humidity History (1981–2025)

Range

Relative humidity in Springfield during September averages 68%. The most humid September was 1993 at 83%, and the least humid was 1999 at 55%.

Springfield September Solar History (1981–2025)

Range

September receives about 4.6 kWh/m²/day of solar energy in Springfield. The sunniest September was 2004 at 5.4 kWh/m²/day, and the cloudiest was 1993 at 3.6.

Springfield September Wind History (1981–2025)

Range

Average wind speed in Springfield during September is 2.5 m/s. The windiest September was 1985 at 3.2 m/s, while the calmest was 2025 at 1.7 m/s.

What September Feels Like in Springfield

🌅
Cool
Morning
🌞
Warm
Afternoon
🌆
Cool
Evening
Rain chanceModerate
Outdoor comfort★★★★☆

How September Ranks in Springfield

🔥4th warmest month of the year
🌵5th driest month of the year
☀️6th sunniest month of the year

Ranked against the other 11 months using 1981–2025 averages.

Explore Springfield Weather by Month

Springfield September Averages by Decade

Metric1980s1990s2000s2010s2020sChange
Avg Temp19.5°C19.1°C19.9°C20.5°C21.1°C+1.6°C
Avg High25.9°C25.6°C26.4°C26.6°C27.7°C+1.8°C
Avg Low13.2°C12.6°C13.4°C14.5°C14.4°C+1.2°C
Avg Rain75 mm70 mm80 mm82 mm60 mm-14 mm

Extreme September Records in Springfield

🔥Warmest September39.6°C2011
🧊Coldest September0.0°C1995
🌧️Wettest September249 mm2008
🏜️Driest September14 mm2004
🌬️Windiest September3.2 m/s1985

Key Insights for September

✅

September temperatures in Springfield have risen by about 2.2°C between 1981–1985 and 2021–2025.

✅

September has ranged from a record low of 0°C (1995) to a record high of 39.6°C (2011).

✅

Rainfall in September is about average for rainfall, averaging 74 mm, with a wettest year of 249 mm.

Is September a Good Time to Visit Springfield?

One of the best times to visit Springfield

September is one of the best times to visit Springfield. Expect days averaging 26.4°C and nights around 13.6°C (mean 20°C) — warmer than Springfield's yearly average — with moderate rainfall (74 mm), so conditions are generally comfortable for sightseeing and outdoor plans.

See Springfield's complete weather history All 12 months side by side, 1981–2025 records, annual trends and long-term averages in one place. View full history →

Springfield Weather in September — In Depth

☀️ September climate overview

September is one of the warmer months of the year in Springfield, with average highs near 26.4°C and lows around 13.6°C (mean 20°C). It is about average for rainfall, averaging 74 mm of rainfall and 68% relative humidity across the period.

🌧️ Rain, humidity & wind in September

September averages 74 mm of rainfall in Springfield, about average for rainfall compared with the rest of the year. The wettest September on record saw 249 mm (2008), and the driest just 14 mm (2004). Humidity sits around 68% and average wind speed is 2.5 m/s, with solar radiation averaging 4.6 kWh/m²/day.

📈 How September has changed

Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 2.2°C. Daytime highs moved from 25.3°C to 28°C and overnight lows from 12.8°C to 14.6°C over the same span.
September Weather in Springfield, Year by Year
🔥 warmest❄️ coldest🌧️ wettest
YearAvg HighAvg TempAvg LowHottest DayColdest DayRainfallHumidityWindSolar
202530.0°C22.5°C15.1°C36.4°C7.5°C32 mm56%1.7 m/s5
202428.4°C21.5°C14.6°C34.0°C8.0°C58 mm60%2.2 m/s4.6
202327.9°C21.5°C15.1°C34.8°C9.4°C69 mm65%2.1 m/s4.7
202226.4°C20.0°C13.7°C33.4°C4.2°C81 mm69%2.4 m/s4.8
202127.3°C21.0°C14.7°C31.9°C8.0°C59 mm71%2.6 m/s5
202026.3°C19.8°C13.3°C32.4°C5.3°C61 mm70%2.5 m/s4.4
2019 🔥28.9°C23.2°C17.4°C32.6°C11.9°C91 mm74%2.5 m/s5
201827.5°C21.7°C15.8°C33.4°C6.3°C72 mm74%2.4 m/s4.7
201729.2°C22.0°C14.8°C35.1°C8.3°C15 mm60%2.3 m/s5.1
201626.3°C21.2°C16.1°C32.2°C10.0°C83 mm79%2.5 m/s4.8
201526.9°C21.1°C15.3°C33.7°C7.5°C82 mm74%2.4 m/s4.8
201424.3°C18.3°C12.3°C32.3°C5.3°C136 mm75%2.3 m/s4.6
201328.7°C21.6°C14.6°C36.3°C7.8°C37 mm65%2.5 m/s5
201225.1°C19.0°C12.9°C32.4°C4.0°C110 mm70%2.5 m/s4.6
201125.0°C18.5°C12.1°C39.6°C5.0°C60 mm65%2.8 m/s4.4
201024.5°C18.9°C13.4°C30.1°C6.7°C132 mm79%2.7 m/s4.7
200923.9°C18.4°C12.9°C26.4°C7.0°C64 mm80%2.1 m/s4.5
2008 🌧️24.4°C19.0°C13.6°C30.8°C8.0°C249 mm81%2.1 m/s4.2
200729.4°C22.2°C15.0°C35.9°C4.3°C41 mm61%2.6 m/s5
200624.8°C18.6°C12.5°C31.1°C4.7°C64 mm69%2.5 m/s4
200529.6°C22.9°C16.1°C35.4°C5.4°C91 mm63%2.4 m/s4.6
200427.5°C20.6°C13.8°C30.7°C7.5°C14 mm65%2.3 m/s5.4
200324.0°C17.8°C11.6°C29.4°C2.3°C76 mm71%2.5 m/s4.8
200227.5°C20.7°C13.9°C33.0°C5.3°C48 mm67%2.1 m/s4.9
200125.5°C18.7°C12.0°C32.4°C3.2°C68 mm68%2.5 m/s5
200027.2°C19.9°C12.7°C35.8°C4.1°C81 mm64%2.9 m/s4.7
199927.2°C19.5°C11.9°C34.5°C4.9°C48 mm55%2.5 m/s5.1
199827.9°C21.5°C15.1°C34.1°C8.1°C38 mm70%2.3 m/s4.6
199726.3°C19.8°C13.2°C32.9°C7.6°C71 mm66%2.5 m/s4.8
199626.0°C19.2°C12.5°C32.5°C5.3°C56 mm63%2.3 m/s4.5
199524.9°C17.9°C10.9°C30.7°C0.0°C24 mm63%2.5 m/s4.6
199425.8°C19.2°C12.6°C33.4°C7.4°C55 mm67%2.1 m/s4.6
1993 ❄️20.8°C15.8°C10.7°C27.0°C1.4°C214 mm83%2.7 m/s3.6
199224.9°C18.2°C11.5°C31.0°C1.2°C80 mm71%2.5 m/s4.5
199125.5°C19.3°C13.2°C33.2°C1.6°C69 mm65%2.4 m/s4.5
199027.1°C20.6°C14.0°C36.6°C3.3°C47 mm67%2.4 m/s4.6
198922.9°C17.1°C11.4°C30.0°C1.0°C111 mm76%2.3 m/s4.3
198829.1°C21.7°C14.2°C33.7°C8.3°C49 mm55%2.9 m/s4.6
198727.2°C20.3°C13.4°C33.7°C7.8°C38 mm65%2.5 m/s4.6
198627.0°C21.5°C15.9°C30.8°C6.8°C199 mm74%2.7 m/s4
198526.1°C19.9°C13.7°C33.8°C4.0°C28 mm67%3.2 m/s4.5
198424.8°C18.5°C12.2°C37.5°C1.2°C103 mm66%2.9 m/s4
198328.0°C20.7°C13.4°C36.4°C1.3°C40 mm59%2.8 m/s—
198224.6°C18.7°C12.9°C30.1°C4.0°C53 mm74%2.5 m/s—
198123.2°C17.5°C11.8°C29.0°C4.7°C51 mm78%2.6 m/s—

Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.

Other Cities in Illinois

Springfield September Weather — FAQ

What is the average temperature in Springfield in September?▼

The average high in September is around 26.4°C with lows near 13.6°C (mean 20°C), based on 45 years of NASA POWER data.

Does it rain a lot in Springfield in September?▼

September averages 74 mm of rainfall in Springfield, about average for rainfall. The wettest on record was 249 mm in 2008.

What was the hottest September on record in Springfield?▼

The hottest September reached 39.6°C in 2011. The coldest dipped to 0°C in 1995.

Has September in Springfield gotten warmer over time?▼

Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 2.2°C. Daytime highs moved from 25.3°C to 28°C and overnight lows from 12.8°C to 14.6°C over the same span.

Is September a good time to visit Springfield?▼

September is one of the warmer months of the year in Springfield and about average for rainfall, so plan for around 26.4°C daytime highs and 13.6°C at night.

Is September the coldest month in Springfield?▼

Not quite — September is the 9th coolest month in Springfield, averaging 20°C.

What should I pack for Springfield in September?▼

For September in Springfield, pack light layers you can adjust through the day, with typical highs of 26.4°C and lows of 13.6°C. Bring an umbrella or light rain jacket too.

Is Springfield humid in September?▼

Relative humidity in September averages 68% — moderately humid.

How windy is Springfield in September?▼

Average wind speed in September is 2.5 m/s. The windiest September on record averaged 3.2 m/s (1985).

Which September had the most rainfall in Springfield?▼

The wettest September on record was 2008 with 249 mm. On average, September sees 74 mm.

Where does this September weather data come from?▼

All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.

Other Illinois cities

Explore how the weather in Springfield behaves each September, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for September specifically, along with year-by-year records and how the month has changed over the decades.