September is one of the warmer months of the year in Oklahoma City, with average highs near 29.9°C and lows around 17.5°C (mean 23.7°C). It is about average for rainfall, averaging 84 mm of rainfall and 62% relative humidity across the period.
September is one of the warmer months of the year in Oklahoma City. Across 45 years of records, the warmest September in Oklahoma City was 1998 — when the month averaged 28.2°C — while the coldest was 1989 at 19.8°C. Typical September days reach 29.9°C with nights near 17.5°C. The long-term trend is warming, about 0.5°C per decade.
September is about average for rainfall in Oklahoma City, averaging 84 mm of rainfall. The wettest September on record was 1986 with 218 mm, while the driest was 2025 at 22 mm.
Relative humidity in Oklahoma City during September averages 62%. The most humid September was 2007 at 79%, and the least humid was 2000 at 40%.
September receives about 5.1 kWh/m²/day of solar energy in Oklahoma City. The sunniest September was 2022 at 5.9 kWh/m²/day, and the cloudiest were 1986 and 2018 at 4.1.
Average wind speed in Oklahoma City during September is 2.9 m/s. The windiest Septembers were 1984, 1985 and 1986, among others at 3.7 m/s, while the calmest were 1990 and 2025 at 2.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 23.1°C | 23.0°C | 23.3°C | 24.6°C | 25.1°C | +2°C |
| Avg High | 29.2°C | 29.1°C | 29.6°C | 30.6°C | 31.7°C | +2.5°C |
| Avg Low | 17.0°C | 16.9°C | 17.0°C | 18.7°C | 18.4°C | +1.4°C |
| Avg Rain | 105 mm | 109 mm | 66 mm | 80 mm | 47 mm | -58 mm |
September temperatures in Oklahoma City have risen by about 1.9°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 1.7°C (1989) to a record high of 42.8°C (1998).
Rainfall in September is about average for rainfall, averaging 84 mm, with a wettest year of 218 mm.
One of the best times to visit Oklahoma City
September is one of the best times to visit Oklahoma City. Expect days averaging 29.9°C and nights around 17.5°C (mean 23.7°C) — warmer than Oklahoma City's yearly average — with higher rainfall (84 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 | 30.4°C | 24.3°C | 18.3°C | 34.2°C | 13.8°C | 22 mm | 64% | 2.2 m/s | 5.1 |
| 2024 | 32.4°C | 25.2°C | 18.0°C | 38.7°C | 13.7°C | 39 mm | 53% | 2.4 m/s | 5.5 |
| 2023 | 33.5°C | 26.7°C | 19.9°C | 40.4°C | 15.3°C | 51 mm | 55% | 2.8 m/s | 5.3 |
| 2022 | 32.9°C | 25.9°C | 18.8°C | 37.5°C | 13.4°C | 31 mm | 51% | 2.8 m/s | 5.9 |
| 2021 | 33.4°C | 26.4°C | 19.4°C | 38.1°C | 11.6°C | 34 mm | 51% | 3.1 m/s | 5.7 |
| 2020 | 27.6°C | 21.8°C | 16.0°C | 33.3°C | 7.7°C | 105 mm | 74% | 2.6 m/s | 4.9 |
| 2019 | 31.7°C | 26.7°C | 21.6°C | 35.2°C | 19.0°C | 66 mm | 72% | 3.1 m/s | 5.4 |
| 2018 | 28.3°C | 23.5°C | 18.8°C | 36.2°C | 9.1°C | 162 mm | 77% | 2.8 m/s | 4.1 |
| 2017 | 29.8°C | 23.8°C | 17.9°C | 35.8°C | 11.6°C | 89 mm | 62% | 2.9 m/s | 5 |
| 2016 | 30.1°C | 24.7°C | 19.2°C | 35.1°C | 10.1°C | 93 mm | 68% | 2.9 m/s | 5.2 |
| 2015 | 31.2°C | 25.2°C | 19.3°C | 36.9°C | 13.4°C | 53 mm | 64% | 3 m/s | 5.4 |
| 2014 | 30.3°C | 24.2°C | 18.2°C | 37.3°C | 9.1°C | 54 mm | 62% | 3.1 m/s | 5.1 |
| 2013 | 31.6°C | 25.1°C | 18.6°C | 37.6°C | 8.8°C | 65 mm | 57% | 2.7 m/s | 5.4 |
| 2012 | 31.5°C | 24.8°C | 18.2°C | 40.8°C | 12.6°C | 77 mm | 53% | 2.8 m/s | 5 |
| 2011 | 30.6°C | 23.2°C | 15.9°C | 40.8°C | 10.9°C | 43 mm | 45% | 3.1 m/s | 5.6 |
| 2010 | 30.5°C | 24.7°C | 18.8°C | 36.8°C | 8.2°C | 94 mm | 66% | 3.3 m/s | 5.4 |
| 2009 | 27.3°C | 21.8°C | 16.3°C | 34.0°C | 9.0°C | 92 mm | 71% | 2.9 m/s | 4.3 |
| 2008 | 28.0°C | 22.0°C | 16.0°C | 32.1°C | 9.4°C | 47 mm | 69% | 2.6 m/s | 5.1 |
| 2007 | 27.9°C | 22.8°C | 17.8°C | 31.5°C | 11.8°C | 60 mm | 79% | 2.8 m/s | 4.9 |
| 2006 | 28.9°C | 22.2°C | 15.4°C | 34.3°C | 9.8°C | 59 mm | 54% | 3 m/s | 5.4 |
| 2005 | 32.1°C | 25.6°C | 19.1°C | 35.3°C | 10.4°C | 70 mm | 60% | 2.9 m/s | 5.7 |
| 2004 | 31.5°C | 24.7°C | 17.9°C | 36.9°C | 11.8°C | 25 mm | 53% | 3.1 m/s | 5.7 |
| 2003 | 27.7°C | 21.6°C | 15.5°C | 32.4°C | 8.9°C | 61 mm | 64% | 3.1 m/s | 4.8 |
| 2002 | 30.9°C | 24.2°C | 17.6°C | 37.2°C | 10.2°C | 95 mm | 58% | 2.7 m/s | 5.5 |
| 2001 | 28.0°C | 22.1°C | 16.1°C | 34.3°C | 6.6°C | 131 mm | 67% | 2.5 m/s | 5.1 |
| 2000 | 33.6°C | 25.9°C | 18.1°C | 42.8°C | 4.9°C | 25 mm | 40% | 3.4 m/s | 5.8 |
| 1999 | 28.6°C | 22.2°C | 15.7°C | 36.7°C | 7.4°C | 105 mm | 60% | 3.1 m/s | 4.8 |
| 1998 🔥 | 34.5°C | 28.2°C | 21.8°C | 42.8°C | 16.5°C | 81 mm | 55% | 2.9 m/s | 5.3 |
| 1997 | 31.3°C | 24.9°C | 18.5°C | 37.2°C | 12.2°C | 74 mm | 59% | 3.1 m/s | 4.9 |
| 1996 | 27.2°C | 21.4°C | 15.5°C | 33.4°C | 5.9°C | 121 mm | 69% | 2.5 m/s | 4.6 |
| 1995 | 27.6°C | 21.9°C | 16.2°C | 38.8°C | 2.9°C | 146 mm | 69% | 2.9 m/s | 4.3 |
| 1994 | 29.0°C | 22.5°C | 16.1°C | 34.9°C | 6.9°C | 59 mm | 61% | 2.9 m/s | 5 |
| 1993 | 27.4°C | 21.0°C | 14.5°C | 32.2°C | 5.9°C | 143 mm | 68% | 3.1 m/s | 5.3 |
| 1992 | 28.2°C | 22.1°C | 16.0°C | 32.2°C | 7.6°C | 64 mm | 71% | 3.1 m/s | 5.2 |
| 1991 | 25.8°C | 20.9°C | 16.0°C | 32.1°C | 6.4°C | 185 mm | 75% | 2.7 m/s | 4.3 |
| 1990 | 31.3°C | 25.2°C | 19.1°C | 38.9°C | 8.6°C | 110 mm | 61% | 2.2 m/s | 5 |
| 1989 ❄️ | 25.7°C | 19.8°C | 13.9°C | 35.1°C | 1.7°C | 137 mm | 69% | 2.8 m/s | 5 |
| 1988 | 30.2°C | 23.3°C | 16.5°C | 37.4°C | 9.7°C | 161 mm | 60% | 2.8 m/s | 5 |
| 1987 | 28.0°C | 21.7°C | 15.4°C | 32.6°C | 8.3°C | 128 mm | 69% | 2.4 m/s | 5.1 |
| 1986 🌧️ | 28.5°C | 24.0°C | 19.4°C | 32.9°C | 10.9°C | 218 mm | 75% | 3.7 m/s | 4.1 |
| 1985 | 29.1°C | 23.3°C | 17.6°C | 39.0°C | 1.8°C | 137 mm | 61% | 3.7 m/s | 5.1 |
| 1984 | 29.6°C | 23.1°C | 16.6°C | 38.6°C | 2.2°C | 35 mm | 49% | 3.7 m/s | 4.7 |
| 1983 | 31.3°C | 24.7°C | 18.1°C | 38.1°C | 4.2°C | 42 mm | 54% | 3.7 m/s | — |
| 1982 | 30.0°C | 23.8°C | 17.5°C | 37.6°C | 7.5°C | 53 mm | 56% | 3.3 m/s | — |
| 1981 | 30.3°C | 24.0°C | 17.7°C | 35.6°C | 7.8°C | 35 mm | 59% | 3.1 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 29.9°C with lows near 17.5°C (mean 23.7°C), based on 45 years of NASA POWER data.
September averages 84 mm of rainfall in Oklahoma City, about average for rainfall. The wettest on record was 218 mm in 1986.
The hottest September reached 42.8°C in 1998. The coldest dipped to 1.7°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.9°C. Daytime highs moved from 30.1°C to 32.5°C and overnight lows from 17.5°C to 18.9°C over the same span.
September is one of the warmer months of the year in Oklahoma City and about average for rainfall, so plan for around 29.9°C daytime highs and 17.5°C at night.
Not quite — September is the 9th coolest month in Oklahoma City, averaging 23.7°C.
For September in Oklahoma City, pack light layers you can adjust through the day, with typical highs of 29.9°C and lows of 17.5°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 62% — moderately humid.
Average wind speed in September is 2.9 m/s. The windiest September on record averaged 3.7 m/s (1983).
The wettest September on record was 1986 with 218 mm. On average, September sees 84 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 Oklahoma City 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.
