September is one of the warmer months of the year in Forest Hills, with average highs near 22.8°C and lows around 17.4°C (mean 20.1°C). It is about average for rainfall, averaging 101 mm of rainfall and 76% relative humidity across the period.
September is one of the warmer months of the year in Forest Hills. Across 45 years of records, the warmest September in Forest Hills was 2005 — when the month averaged 22.2°C — while the coldest was 1984 at 18.1°C. Typical September days reach 22.8°C with nights near 17.4°C. The long-term trend is warming, about 0.5°C per decade.
September is about average for rainfall in Forest Hills, averaging 101 mm of rainfall. The wettest September on record was 2023 with 308 mm, while the driest was 2024 at 20 mm.
Relative humidity in Forest Hills during September averages 76%. The most humid September was 2011 at 87%, and the least humid was 1983 at 68%.
September receives about 4.4 kWh/m²/day of solar energy in Forest Hills. The sunniest Septembers were 1984, 2005 and 2007 at 5 kWh/m²/day, and the cloudiest was 2018 at 3.7.
Average wind speed in Forest Hills during September is 3.8 m/s. The windiest September was 2010 at 4.3 m/s, while the calmest was 1982 at 3.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 19.3°C | 19.5°C | 20.2°C | 20.8°C | 20.8°C | +1.5°C |
| Avg High | 22.3°C | 22.2°C | 22.8°C | 23.4°C | 23.3°C | +1°C |
| Avg Low | 16.4°C | 16.8°C | 17.5°C | 18.2°C | 18.3°C | +1.9°C |
| Avg Rain | 88 mm | 104 mm | 105 mm | 94 mm | 124 mm | +35 mm |
September temperatures in Forest Hills have risen by about 1.4°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 8.9°C (2000) to a record high of 31.1°C (2023).
Rainfall in September is about average for rainfall, averaging 101 mm, with a wettest year of 308 mm.
One of the best times to visit Forest Hills
September is one of the best times to visit Forest Hills. Expect days averaging 22.8°C and nights around 17.4°C (mean 20.1°C) — warmer than Forest Hills's yearly average — with higher rainfall (101 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 | 23.7°C | 21.2°C | 18.6°C | 27.1°C | 16.0°C | 69 mm | 76% | 3.5 m/s | 4.5 |
| 2024 | 22.8°C | 20.3°C | 17.9°C | 26.2°C | 14.8°C | 20 mm | 77% | 3.7 m/s | 4.3 |
| 2023 🌧️ | 23.3°C | 20.9°C | 18.5°C | 31.1°C | 13.8°C | 308 mm | 80% | 3.9 m/s | 4 |
| 2022 | 23.8°C | 21.0°C | 18.2°C | 28.2°C | 11.5°C | 127 mm | 74% | 3.9 m/s | 4.6 |
| 2021 | 23.3°C | 20.9°C | 18.5°C | 26.5°C | 14.1°C | 137 mm | 82% | 3.9 m/s | 4.6 |
| 2020 | 23.0°C | 20.4°C | 17.9°C | 27.7°C | 11.6°C | 80 mm | 77% | 3.9 m/s | 4.4 |
| 2019 | 23.6°C | 20.8°C | 18.0°C | 26.3°C | 13.2°C | 33 mm | 76% | 3.6 m/s | 4.7 |
| 2018 | 23.4°C | 21.5°C | 19.6°C | 30.2°C | 15.1°C | 221 mm | 86% | 3.7 m/s | 3.7 |
| 2017 | 23.1°C | 20.4°C | 17.6°C | 27.2°C | 13.3°C | 63 mm | 79% | 3.7 m/s | 4.4 |
| 2016 | 24.0°C | 21.5°C | 19.1°C | 28.9°C | 14.0°C | 97 mm | 75% | 4 m/s | 4.1 |
| 2015 | 24.8°C | 22.0°C | 19.2°C | 29.4°C | 15.2°C | 80 mm | 76% | 3.7 m/s | 4.8 |
| 2014 | 23.2°C | 20.6°C | 18.0°C | 28.7°C | 12.7°C | 42 mm | 74% | 3.5 m/s | 4.5 |
| 2013 | 22.2°C | 19.0°C | 15.9°C | 27.7°C | 10.7°C | 50 mm | 73% | 3.6 m/s | 4.9 |
| 2012 | 23.3°C | 20.7°C | 18.2°C | 29.3°C | 14.2°C | 107 mm | 75% | 3.8 m/s | 4.5 |
| 2011 | 22.3°C | 20.2°C | 18.2°C | 25.7°C | 11.8°C | 150 mm | 87% | 3.5 m/s | 3.9 |
| 2010 | 24.2°C | 21.3°C | 18.4°C | 29.6°C | 14.1°C | 101 mm | 74% | 4.3 m/s | 4.5 |
| 2009 | 21.8°C | 19.3°C | 16.7°C | 26.7°C | 11.3°C | 72 mm | 77% | 3.9 m/s | 4.3 |
| 2008 | 22.6°C | 20.2°C | 17.8°C | 28.3°C | 13.7°C | 181 mm | 80% | 3.7 m/s | 4.3 |
| 2007 | 23.5°C | 20.7°C | 17.9°C | 26.5°C | 13.0°C | 27 mm | 75% | 3.6 m/s | 5 |
| 2006 | 21.8°C | 19.3°C | 16.8°C | 25.5°C | 12.7°C | 108 mm | 79% | 4 m/s | 4.1 |
| 2005 🔥 | 25.3°C | 22.2°C | 19.1°C | 29.0°C | 12.1°C | 31 mm | 70% | 3.5 m/s | 5 |
| 2004 | 23.2°C | 20.7°C | 18.2°C | 26.5°C | 12.6°C | 167 mm | 80% | 3.6 m/s | 4.4 |
| 2003 | 22.1°C | 19.9°C | 17.7°C | 24.4°C | 12.0°C | 131 mm | 83% | 4.1 m/s | 4.1 |
| 2002 | 23.3°C | 20.6°C | 17.9°C | 27.9°C | 14.5°C | 114 mm | 77% | 3.8 m/s | 4.6 |
| 2001 | 22.6°C | 19.8°C | 16.9°C | 26.3°C | 11.9°C | 80 mm | 73% | 3.9 m/s | 4.7 |
| 2000 | 21.6°C | 18.8°C | 16.0°C | 26.8°C | 8.9°C | 134 mm | 78% | 3.9 m/s | 4.4 |
| 1999 | 22.5°C | 20.1°C | 17.7°C | 25.7°C | 11.6°C | 204 mm | 81% | 4.2 m/s | 4.2 |
| 1998 | 23.7°C | 20.7°C | 17.7°C | 28.3°C | 12.2°C | 60 mm | 74% | 3.7 m/s | 4.7 |
| 1997 | 22.0°C | 19.1°C | 16.2°C | 25.8°C | 11.3°C | 56 mm | 75% | 4.2 m/s | 4.4 |
| 1996 | 22.2°C | 19.6°C | 17.1°C | 27.9°C | 11.9°C | 143 mm | 81% | 4.1 m/s | 3.9 |
| 1995 | 22.4°C | 19.7°C | 17.1°C | 27.6°C | 12.7°C | 99 mm | 70% | 4.1 m/s | 4.4 |
| 1994 | 21.7°C | 18.6°C | 15.6°C | 25.9°C | 12.0°C | 77 mm | 75% | 4.1 m/s | 4.5 |
| 1993 | 22.2°C | 19.6°C | 17.0°C | 28.3°C | 10.5°C | 146 mm | 77% | 3.9 m/s | 3.8 |
| 1992 | 21.5°C | 19.0°C | 16.6°C | 25.2°C | 9.3°C | 89 mm | 78% | 4.2 m/s | 3.9 |
| 1991 | 22.2°C | 19.4°C | 16.6°C | 28.5°C | 9.4°C | 105 mm | 72% | 3.9 m/s | 4.3 |
| 1990 | 21.8°C | 19.1°C | 16.4°C | 26.9°C | 10.4°C | 60 mm | 77% | 3.7 m/s | 4.3 |
| 1989 | 22.1°C | 19.5°C | 16.9°C | 28.3°C | 9.6°C | 157 mm | 79% | 4 m/s | 4.3 |
| 1988 | 21.7°C | 18.5°C | 15.3°C | 24.6°C | 11.5°C | 68 mm | 73% | 3.5 m/s | 4.6 |
| 1987 | 21.8°C | 19.3°C | 16.8°C | 25.8°C | 12.4°C | 115 mm | 81% | 3.7 m/s | 4.3 |
| 1986 | 21.9°C | 19.0°C | 16.2°C | 26.1°C | 10.0°C | 59 mm | 75% | 3.7 m/s | 4.3 |
| 1985 | 23.3°C | 20.3°C | 17.2°C | 29.5°C | 12.7°C | 107 mm | 72% | 3.6 m/s | 4.7 |
| 1984 ❄️ | 21.1°C | 18.1°C | 15.1°C | 25.3°C | 9.4°C | 69 mm | 73% | 3.7 m/s | 5 |
| 1983 | 24.2°C | 20.8°C | 17.5°C | 30.5°C | 12.0°C | 84 mm | 68% | 3.7 m/s | — |
| 1982 | 22.5°C | 19.4°C | 16.4°C | 27.8°C | 13.2°C | 50 mm | 73% | 3.4 m/s | — |
| 1981 | 21.8°C | 18.8°C | 15.8°C | 27.2°C | 10.1°C | 88 mm | 73% | 4.1 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 22.8°C with lows near 17.4°C (mean 20.1°C), based on 45 years of NASA POWER data.
September averages 101 mm of rainfall in Forest Hills, about average for rainfall. The wettest on record was 308 mm in 2023.
The hottest September reached 31.1°C in 2023. The coldest dipped to 8.9°C in 2000.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.4°C. Daytime highs moved from 22.6°C to 23.4°C and overnight lows from 16.4°C to 18.3°C over the same span.
September is one of the warmer months of the year in Forest Hills and about average for rainfall, so plan for around 22.8°C daytime highs and 17.4°C at night.
Not quite — September is the 10th coolest month in Forest Hills, averaging 20.1°C.
For September in Forest Hills, pack light layers you can adjust through the day, with typical highs of 22.8°C and lows of 17.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 76% — quite humid.
Average wind speed in September is 3.8 m/s. The windiest September on record averaged 4.3 m/s (2010).
The wettest September on record was 2023 with 308 mm. On average, September sees 101 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 Forest Hills 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.
