Butler Weather in September (1981–2025)

📍 40.86°N, 79.90°W •
📊

September at a Glance in Butler

(1981–2025)
Avg High
🔥
24.4°C
Avg Low
❄️
11.5°C
Avg Temp
🌡️
18.0°C
Avg Rain
🌧️
87 mm
Avg Humidity
💧
72%
Avg Wind
🌬️
0.1 m/s
Avg Solar
☀️
4.2
kWh/m²/day
vs Annual
📈
+8.4°C
temp difference
🌤️Mild afternoons🌤️Cool mornings🌤️Fairly sunny🌧️Wet month🍃Light winds😊Comfortable humidity

Butler September Weather Overview

September is one of the warmer months of the year in Butler, with average highs near 24.4°C and lows around 11.5°C (mean 18°C). It is about average for rainfall, averaging 87 mm of rainfall and 72% relative humidity across the period.

Butler September Temperature History (1981–2025)

Range

September is one of the warmer months of the year in Butler. Across 45 years of records, the warmest September in Butler was 2016 — when the month averaged 20.8°C — while the coldest were 1984 and 2006 at 15.7°C. Typical September days reach 24.4°C with nights near 11.5°C. The long-term trend is warming, about 0.6°C per decade.

1981–1985 vs 2021–2025

Avg Temp17.0°C→19.1°C+2.1°C
Max Temp23.6°C→25.8°C+2.2°C
Min Temp10.3°C→12.4°C+2.1°C

Trend (per decade)

Avg Temp+0.6°C/decade ↗
Max Temp+0.7°C/decade ↗
Min Temp+0.6°C/decade ↗

Distribution of Avg Temp

15.0°C–16.5°C8 yr (18%)
16.5°C–18.0°C16 yr (36%)
18.0°C–19.5°C12 yr (27%)
19.5°C–21.0°C9 yr (20%)

Butler September Rainfall History (1981–2025)

Range

September is about average for rainfall in Butler, averaging 87 mm of rainfall. The wettest September on record was 2004 with 185 mm, while the driest was 2017 at 33 mm.

Butler September Humidity History (1981–2025)

Range

Relative humidity in Butler during September averages 72%. The most humid September was 2011 at 83%, and the least humid were 1991 and 1999 at 62%.

Butler September Solar History (1981–2025)

Range

September receives about 4.2 kWh/m²/day of solar energy in Butler. The sunniest September was 2007 at 5 kWh/m²/day, and the cloudiest was 1993 at 3.3.

Butler September Wind History (1981–2025)

Range

Average wind speed in Butler during September is 0.1 m/s. The windiest Septembers were 2022, 2023 and 2025, among others at 0.1 m/s, while the calmest were 2018, 2021 and 2024, among others at 0 m/s.

What September Feels Like in Butler

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

How September Ranks in Butler

🔥4th warmest month of the year
🌧️5th wettest month of the year
☀️6th sunniest month of the year

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

Explore Butler Weather by Month

Butler September Averages by Decade

Metric1980s1990s2000s2010s2020sChange
Avg Temp17.1°C17.1°C18.0°C18.9°C18.9°C+1.8°C
Avg High23.6°C23.6°C24.4°C25.3°C25.6°C+2°C
Avg Low10.6°C10.6°C11.5°C12.5°C12.2°C+1.6°C
Avg Rain87 mm95 mm90 mm90 mm65 mm-23 mm

Extreme September Records in Butler

🔥Warmest September35.5°C2011
🧊Coldest September0.4°C1989
🌧️Wettest September185 mm2004
🏜️Driest September33 mm2017
🌬️Windiest September0.1 m/s1981

Key Insights for September

✅

September temperatures in Butler have risen by about 2.1°C between 1981–1985 and 2021–2025.

✅

September has ranged from a record low of 0.4°C (1989) to a record high of 35.5°C (2011).

✅

Rainfall in September is about average for rainfall, averaging 87 mm, with a wettest year of 185 mm.

Is September a Good Time to Visit Butler?

One of the best times to visit Butler

September is one of the best times to visit Butler. Expect days averaging 24.4°C and nights around 11.5°C (mean 18°C) — warmer than Butler's yearly average — with higher rainfall (87 mm), so conditions are generally comfortable for sightseeing and outdoor plans.

See Butler'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 →

Butler Weather in September — In Depth

☀️ September climate overview

September is one of the warmer months of the year in Butler, with average highs near 24.4°C and lows around 11.5°C (mean 18°C). It is about average for rainfall, averaging 87 mm of rainfall and 72% relative humidity across the period.

🌧️ Rain, humidity & wind in September

September averages 87 mm of rainfall in Butler, about average for rainfall compared with the rest of the year. The wettest September on record saw 185 mm (2004), and the driest just 33 mm (2017). Humidity sits around 72% and average wind speed is 0.1 m/s, with solar radiation averaging 4.2 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 2.1°C. Daytime highs moved from 23.6°C to 25.8°C and overnight lows from 10.3°C to 12.4°C over the same span.
September Weather in Butler, Year by Year
🔥 warmest❄️ coldest🌧️ wettest
YearAvg HighAvg TempAvg LowHottest DayColdest DayRainfallHumidityWindSolar
202527.4°C19.8°C12.3°C30.8°C6.7°C64 mm62%0.1 m/s4.6
202426.6°C19.9°C13.3°C31.4°C6.5°C78 mm68%0 m/s4.4
202325.4°C18.9°C12.3°C33.9°C6.2°C36 mm72%0.1 m/s4.4
202224.3°C18.3°C12.2°C30.6°C3.8°C90 mm74%0.1 m/s4
202125.2°C18.6°C12.1°C30.3°C6.3°C64 mm73%0 m/s4.4
202024.7°C18.0°C11.3°C30.6°C3.2°C56 mm70%0.1 m/s4.4
201926.3°C19.9°C13.4°C30.7°C8.1°C76 mm75%0.1 m/s4.6
201825.2°C20.1°C14.9°C35.2°C6.4°C170 mm83%0 m/s3.5
201726.1°C19.3°C12.5°C33.5°C5.5°C33 mm67%0.1 m/s4.4
2016 🔥27.7°C20.8°C13.8°C33.4°C8.0°C93 mm67%0.1 m/s4.7
201527.3°C20.6°C13.9°C33.8°C7.5°C97 mm67%0.1 m/s4.5
201424.7°C17.8°C10.9°C31.2°C5.2°C36 mm71%0.1 m/s4.6
201323.8°C17.1°C10.3°C33.1°C2.8°C51 mm71%0 m/s4.4
201223.4°C17.1°C10.9°C30.9°C4.3°C119 mm73%0.1 m/s4
201123.2°C18.0°C12.9°C35.5°C3.8°C152 mm83%0.1 m/s3.5
201024.8°C18.3°C11.9°C34.1°C7.9°C77 mm65%0 m/s4.3
200923.4°C17.6°C11.7°C28.5°C4.2°C59 mm72%0 m/s3.9
200825.5°C18.8°C12.0°C33.2°C7.8°C68 mm69%0.1 m/s4.3
200726.3°C19.1°C12.0°C33.0°C4.4°C54 mm69%0.1 m/s5
200620.7°C15.7°C10.7°C27.5°C4.2°C133 mm81%0.1 m/s3.5
200527.0°C19.8°C12.7°C32.0°C3.8°C62 mm66%0.1 m/s4.8
2004 🌧️23.8°C17.9°C12.0°C28.2°C5.0°C185 mm81%0.1 m/s4.4
200322.0°C16.4°C10.9°C26.4°C4.2°C129 mm82%0.1 m/s3.6
200227.4°C20.1°C12.9°C34.8°C7.6°C78 mm63%0.1 m/s4.6
200124.1°C16.9°C9.8°C32.7°C4.0°C52 mm65%0 m/s4.7
200024.2°C17.2°C10.2°C33.0°C0.5°C81 mm69%0 m/s4.2
199925.7°C18.3°C11.0°C33.5°C1.5°C65 mm62%0.1 m/s4.3
199826.9°C19.6°C12.3°C34.2°C4.9°C49 mm65%0.1 m/s4.7
199723.0°C16.7°C10.3°C29.5°C3.6°C101 mm73%0.1 m/s4.2
199622.0°C16.9°C11.8°C30.0°C6.5°C164 mm81%0.1 m/s3.5
199524.0°C16.8°C9.6°C30.9°C0.9°C41 mm64%0.1 m/s4.2
199422.6°C16.3°C10.0°C29.3°C4.9°C77 mm73%0.1 m/s4.2
199322.4°C16.4°C10.4°C30.7°C1.7°C111 mm73%0.1 m/s3.3
199222.6°C16.3°C9.9°C28.0°C0.7°C108 mm78%0.1 m/s4.1
199124.7°C17.6°C10.4°C32.6°C2.7°C73 mm62%0.1 m/s4.2
199021.7°C16.2°C10.6°C29.0°C2.7°C157 mm82%0.1 m/s3.7
198923.4°C17.1°C10.8°C30.0°C0.4°C122 mm77%0 m/s3.8
198823.7°C16.7°C9.7°C29.5°C4.8°C72 mm73%0.1 m/s4.1
198722.4°C16.9°C11.3°C26.1°C2.8°C122 mm81%0.1 m/s3.8
198625.2°C18.7°C12.2°C28.8°C2.1°C103 mm71%0.1 m/s4.3
198525.6°C18.4°C11.2°C31.6°C3.3°C43 mm64%0.1 m/s4.7
1984 ❄️22.2°C15.7°C9.1°C30.2°C2.8°C53 mm73%0.1 m/s4.5
198325.0°C17.9°C10.7°C33.3°C1.4°C75 mm65%0.1 m/s—
198223.6°C17.0°C10.3°C31.3°C4.6°C84 mm71%0.1 m/s—
198121.4°C15.9°C10.4°C28.5°C1.8°C112 mm78%0.1 m/s—

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

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Butler September Weather — FAQ

What is the average temperature in Butler in September?▼

The average high in September is around 24.4°C with lows near 11.5°C (mean 18°C), based on 45 years of NASA POWER data.

Does it rain a lot in Butler in September?▼

September averages 87 mm of rainfall in Butler, about average for rainfall. The wettest on record was 185 mm in 2004.

What was the hottest September on record in Butler?▼

The hottest September reached 35.5°C in 2011. The coldest dipped to 0.4°C in 1989.

Has September in Butler 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 2.1°C. Daytime highs moved from 23.6°C to 25.8°C and overnight lows from 10.3°C to 12.4°C over the same span.

Is September a good time to visit Butler?▼

September is one of the warmer months of the year in Butler and about average for rainfall, so plan for around 24.4°C daytime highs and 11.5°C at night.

Is September the coldest month in Butler?▼

Not quite — September is the 9th coolest month in Butler, averaging 18°C.

What should I pack for Butler in September?▼

For September in Butler, pack light layers you can adjust through the day, with typical highs of 24.4°C and lows of 11.5°C. Bring an umbrella or light rain jacket too.

Is Butler humid in September?▼

Relative humidity in September averages 72% — moderately humid.

How windy is Butler in September?▼

Average wind speed in September is 0.1 m/s. The windiest September on record averaged 0.1 m/s (1981).

Which September had the most rainfall in Butler?▼

The wettest September on record was 2004 with 185 mm. On average, September sees 87 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 Pennsylvania cities

Explore how the weather in Butler 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.