September is one of the warmer months of the year in East Hartford, with average highs near 24°C and lows around 11.7°C (mean 17.9°C). It is about average for rainfall, averaging 106 mm of rainfall and 74% relative humidity across the period.
September is one of the warmer months of the year in East Hartford. Across 45 years of records, the warmest September in East Hartford was 2015 — when the month averaged 20.7°C — while the coldest was 1984 at 15.6°C. Typical September days reach 24°C with nights near 11.7°C. The long-term trend is warming, about 0.6°C per decade.
September is about average for rainfall in East Hartford, averaging 106 mm of rainfall. The wettest September on record was 2023 with 223 mm, while the driest was 2024 at 29 mm.
Relative humidity in East Hartford during September averages 74%. The most humid September was 2011 at 86%, and the least humid was 1983 at 62%.
September receives about 4.3 kWh/m²/day of solar energy in East Hartford. The sunniest September was 2007 at 5 kWh/m²/day, and the cloudiest was 2018 at 3.4.
Average wind speed in East Hartford during September is 0.1 m/s. The windiest Septembers were 2023, 2024 and 2025, among others at 0.1 m/s, while the calmest were 1998, 2003 and 2010, among others at 0 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 16.9°C | 17.1°C | 18.1°C | 18.9°C | 18.5°C | +1.6°C |
| Avg High | 23.2°C | 23.1°C | 24.3°C | 25.0°C | 24.5°C | +1.3°C |
| Avg Low | 10.5°C | 11.1°C | 11.9°C | 12.8°C | 12.7°C | +2.2°C |
| Avg Rain | 83 mm | 112 mm | 108 mm | 106 mm | 125 mm | +42 mm |
September temperatures in East Hartford have risen by about 1.3°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -0.2°C (1991) to a record high of 36.6°C (2002).
Rainfall in September is about average for rainfall, averaging 106 mm, with a wettest year of 223 mm.
One of the best times to visit East Hartford
September is one of the best times to visit East Hartford. Expect days averaging 24°C and nights around 11.7°C (mean 17.9°C) — warmer than East Hartford's yearly average — with higher rainfall (106 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 25.8°C | 19.3°C | 12.8°C | 29.4°C | 9.1°C | 88 mm | 72% | 0.1 m/s | 4.6 |
| 2024 | 25.2°C | 18.7°C | 12.2°C | 30.5°C | 8.8°C | 29 mm | 71% | 0.1 m/s | 4.3 |
| 2023 🌧️ | 23.7°C | 18.7°C | 13.8°C | 34.6°C | 6.2°C | 223 mm | 82% | 0.1 m/s | 3.9 |
| 2022 | 23.4°C | 17.7°C | 12.1°C | 31.1°C | 5.8°C | 163 mm | 78% | 0.1 m/s | 4.4 |
| 2021 | 23.5°C | 18.3°C | 13.1°C | 28.2°C | 7.3°C | 185 mm | 82% | 0.1 m/s | 4.2 |
| 2020 | 25.1°C | 18.5°C | 12.0°C | 32.3°C | 2.9°C | 60 mm | 67% | 0.1 m/s | 4.4 |
| 2019 | 24.9°C | 18.3°C | 11.8°C | 31.1°C | 4.4°C | 49 mm | 70% | 0.1 m/s | 4.6 |
| 2018 | 24.3°C | 19.3°C | 14.3°C | 33.9°C | 6.4°C | 219 mm | 82% | 0.1 m/s | 3.4 |
| 2017 | 25.8°C | 19.7°C | 13.6°C | 34.1°C | 6.4°C | 65 mm | 72% | 0.1 m/s | 4.3 |
| 2016 | 26.1°C | 19.9°C | 13.6°C | 32.8°C | 4.6°C | 60 mm | 68% | 0.1 m/s | 4.2 |
| 2015 🔥 | 27.9°C | 20.7°C | 13.5°C | 35.2°C | 5.3°C | 127 mm | 70% | 0.1 m/s | 4.8 |
| 2014 | 25.0°C | 18.4°C | 11.8°C | 32.3°C | 5.3°C | 36 mm | 70% | 0.1 m/s | 4.5 |
| 2013 | 23.2°C | 16.7°C | 10.2°C | 34.2°C | 3.7°C | 72 mm | 73% | 0.1 m/s | 4.6 |
| 2012 | 23.4°C | 17.5°C | 11.6°C | 30.8°C | 5.4°C | 141 mm | 76% | 0.1 m/s | 4.3 |
| 2011 | 23.6°C | 18.8°C | 13.9°C | 28.3°C | 4.9°C | 214 mm | 86% | 0.1 m/s | 4.1 |
| 2010 | 25.8°C | 19.7°C | 13.6°C | 35.6°C | 6.5°C | 78 mm | 69% | 0 m/s | 4.3 |
| 2009 | 22.3°C | 16.4°C | 10.5°C | 27.3°C | 4.0°C | 46 mm | 76% | 0.1 m/s | 4.6 |
| 2008 | 23.0°C | 17.4°C | 11.9°C | 31.6°C | 4.9°C | 217 mm | 81% | 0.1 m/s | 4.2 |
| 2007 | 26.4°C | 19.4°C | 12.3°C | 33.6°C | 5.1°C | 58 mm | 68% | 0.1 m/s | 5 |
| 2006 | 21.9°C | 16.4°C | 10.9°C | 27.0°C | 4.7°C | 74 mm | 80% | 0.1 m/s | 4 |
| 2005 | 27.2°C | 20.3°C | 13.4°C | 34.2°C | 6.8°C | 60 mm | 67% | 0.1 m/s | 4.8 |
| 2004 | 24.1°C | 18.1°C | 12.2°C | 30.3°C | 6.2°C | 204 mm | 79% | 0.1 m/s | 4.3 |
| 2003 | 23.5°C | 18.0°C | 12.5°C | 28.4°C | 6.8°C | 156 mm | 80% | 0 m/s | 4 |
| 2002 | 26.2°C | 19.7°C | 13.2°C | 36.6°C | 6.3°C | 88 mm | 69% | 0.1 m/s | 4.4 |
| 2001 | 24.7°C | 18.0°C | 11.4°C | 32.3°C | 5.7°C | 92 mm | 69% | 0.1 m/s | 4.7 |
| 2000 | 23.4°C | 16.9°C | 10.5°C | 30.1°C | -0.1°C | 83 mm | 72% | 0.1 m/s | 4.2 |
| 1999 | 24.5°C | 18.8°C | 13.0°C | 35.0°C | 6.1°C | 218 mm | 77% | 0.1 m/s | 4 |
| 1998 | 25.8°C | 18.8°C | 11.8°C | 32.0°C | 3.6°C | 61 mm | 68% | 0 m/s | 4.5 |
| 1997 | 23.4°C | 17.1°C | 10.9°C | 28.9°C | 3.0°C | 41 mm | 70% | 0.1 m/s | 4.2 |
| 1996 | 22.7°C | 17.5°C | 12.3°C | 31.1°C | 4.9°C | 164 mm | 78% | 0.1 m/s | 3.6 |
| 1995 | 23.3°C | 16.6°C | 9.9°C | 30.4°C | 2.9°C | 85 mm | 65% | 0.1 m/s | 4.4 |
| 1994 | 21.9°C | 16.3°C | 10.7°C | 27.9°C | 7.1°C | 114 mm | 75% | 0.1 m/s | 4.2 |
| 1993 | 22.4°C | 16.9°C | 11.3°C | 31.4°C | 1.5°C | 140 mm | 77% | 0.1 m/s | 3.5 |
| 1992 | 22.5°C | 16.5°C | 10.5°C | 29.8°C | 1.1°C | 83 mm | 75% | 0.1 m/s | 4 |
| 1991 | 21.7°C | 15.8°C | 9.9°C | 31.5°C | -0.2°C | 159 mm | 75% | 0.1 m/s | 4.3 |
| 1990 | 22.6°C | 16.4°C | 10.3°C | 29.6°C | 2.4°C | 54 mm | 75% | 0.1 m/s | 4.4 |
| 1989 | 22.7°C | 16.7°C | 10.7°C | 32.6°C | 1.1°C | 123 mm | 78% | 0.1 m/s | 4.3 |
| 1988 | 22.6°C | 16.0°C | 9.4°C | 28.1°C | 3.8°C | 57 mm | 71% | 0.1 m/s | 4.7 |
| 1987 | 21.7°C | 16.4°C | 11.1°C | 27.2°C | 2.5°C | 156 mm | 80% | 0 m/s | 3.9 |
| 1986 | 23.1°C | 16.7°C | 10.3°C | 29.9°C | 3.8°C | 33 mm | 69% | 0.1 m/s | 4 |
| 1985 | 23.5°C | 17.2°C | 10.8°C | 29.6°C | 4.1°C | 114 mm | 76% | 0.1 m/s | 4.4 |
| 1984 ❄️ | 22.1°C | 15.6°C | 9.0°C | 29.1°C | 4.1°C | 43 mm | 69% | 0.1 m/s | 4.6 |
| 1983 | 26.6°C | 19.2°C | 11.7°C | 34.8°C | 4.5°C | 52 mm | 62% | 0.1 m/s | — |
| 1982 | 24.3°C | 17.6°C | 11.0°C | 31.3°C | 7.2°C | 61 mm | 71% | 0.1 m/s | — |
| 1981 | 22.5°C | 16.4°C | 10.3°C | 30.0°C | 1.8°C | 105 mm | 71% | 0.1 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 24°C with lows near 11.7°C (mean 17.9°C), based on 45 years of NASA POWER data.
September averages 106 mm of rainfall in East Hartford, about average for rainfall. The wettest on record was 223 mm in 2023.
The hottest September reached 36.6°C in 2002. The coldest dipped to -0.2°C in 1991.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.3°C. Daytime highs moved from 23.8°C to 24.3°C and overnight lows from 10.6°C to 12.8°C over the same span.
September is one of the warmer months of the year in East Hartford and about average for rainfall, so plan for around 24°C daytime highs and 11.7°C at night.
Not quite — September is the 9th coolest month in East Hartford, averaging 17.9°C.
For September in East Hartford, pack light layers you can adjust through the day, with typical highs of 24°C and lows of 11.7°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 74% — moderately humid.
Average wind speed in September is 0.1 m/s. The windiest September on record averaged 0.1 m/s (1981).
The wettest September on record was 2023 with 223 mm. On average, September sees 106 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in East Hartford 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.
