September is one of the warmer months of the year in Rexburg, with average highs near 22.1°C and lows around 6.9°C (mean 14.5°C). It is one of the drier months, averaging 35 mm of rainfall and 48% relative humidity across the period.
September is one of the warmer months of the year in Rexburg. Across 45 years of records, the warmest September in Rexburg was 2022 — when the month averaged 17.9°C — while the coldest was 1985 at 10.1°C. Typical September days reach 22.1°C with nights near 6.9°C. The long-term trend is warming, about 0.6°C per decade.
September is one of the drier months in Rexburg, averaging 35 mm of rainfall. The wettest September on record was 2017 with 87 mm, while the driest was 1987 at 1 mm.
Relative humidity in Rexburg during September averages 48%. The most humid September was 2017 at 60%, and the least humid was 1994 at 33%.
September receives about 5 kWh/m²/day of solar energy in Rexburg. The sunniest September was 1999 at 5.6 kWh/m²/day, and the cloudiest was 2013 at 4.2.
Average wind speed in Rexburg during September is 2.1 m/s. The windiest September was 2013 at 2.6 m/s, while the calmest were 1991, 1998 and 2011, among others at 1.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 13.1°C | 14.5°C | 14.5°C | 14.8°C | 16.3°C | +3.2°C |
| Avg High | 20.9°C | 22.1°C | 22.2°C | 22.1°C | 24.0°C | +3.1°C |
| Avg Low | 5.4°C | 6.9°C | 6.6°C | 7.5°C | 8.7°C | +3.3°C |
| Avg Rain | 34 mm | 28 mm | 32 mm | 48 mm | 34 mm | 0 mm |
September temperatures in Rexburg have risen by about 3.7°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -6.9°C (1983) to a record high of 35.3°C (2022).
Rainfall in September is one of the drier months, averaging 35 mm, with a wettest year of 87 mm.
One of the best times to visit Rexburg
September is one of the best times to visit Rexburg. Expect days averaging 22.1°C and nights around 6.9°C (mean 14.5°C) — warmer than Rexburg's yearly average — with moderate rainfall (35 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 | 24.6°C | 17.3°C | 10.1°C | 32.6°C | 4.7°C | 23 mm | 48% | 1.9 m/s | 4.9 |
| 2024 | 24.4°C | 16.8°C | 9.2°C | 30.9°C | 1.6°C | 44 mm | 48% | 2 m/s | 5 |
| 2023 | 22.2°C | 15.3°C | 8.3°C | 28.2°C | 2.5°C | 57 mm | 56% | 1.9 m/s | 4.7 |
| 2022 🔥 | 25.7°C | 17.9°C | 10.0°C | 35.3°C | 4.1°C | 38 mm | 43% | 2 m/s | 5.1 |
| 2021 | 23.4°C | 15.4°C | 7.4°C | 31.1°C | 1.1°C | 22 mm | 41% | 2 m/s | 5.3 |
| 2020 | 23.7°C | 15.4°C | 7.2°C | 32.8°C | -1.2°C | 20 mm | 45% | 2 m/s | 5.3 |
| 2019 | 20.5°C | 14.1°C | 7.6°C | 33.1°C | -3.2°C | 86 mm | 58% | 2.2 m/s | 4.4 |
| 2018 | 22.7°C | 14.9°C | 7.1°C | 28.8°C | 0.7°C | 2 mm | 44% | 2 m/s | 5.5 |
| 2017 🌧️ | 19.9°C | 13.3°C | 6.6°C | 31.0°C | -2.8°C | 87 mm | 60% | 2 m/s | 4.3 |
| 2016 | 20.6°C | 13.9°C | 7.1°C | 31.0°C | 1.9°C | 62 mm | 55% | 2.1 m/s | 4.6 |
| 2015 | 23.3°C | 15.9°C | 8.4°C | 29.4°C | 2.7°C | 48 mm | 47% | 2.2 m/s | 5.2 |
| 2014 | 22.0°C | 14.6°C | 7.2°C | 27.6°C | -3.4°C | 72 mm | 58% | 2.1 m/s | 5.1 |
| 2013 | 21.4°C | 15.1°C | 8.8°C | 31.1°C | 0.9°C | 60 mm | 58% | 2.6 m/s | 4.2 |
| 2012 | 23.8°C | 15.8°C | 7.8°C | 28.2°C | 3.3°C | 23 mm | 44% | 1.8 m/s | 5.3 |
| 2011 | 24.0°C | 16.0°C | 8.1°C | 27.4°C | 3.8°C | 21 mm | 50% | 1.7 m/s | 5.4 |
| 2010 | 22.7°C | 14.5°C | 6.3°C | 28.4°C | 1.2°C | 20 mm | 46% | 2.1 m/s | 5.3 |
| 2009 | 25.1°C | 16.8°C | 8.6°C | 29.4°C | 1.0°C | 15 mm | 46% | 1.9 m/s | 5.3 |
| 2008 | 21.9°C | 13.7°C | 5.5°C | 27.4°C | 1.0°C | 17 mm | 44% | 1.8 m/s | 5.3 |
| 2007 | 21.7°C | 14.0°C | 6.3°C | 32.0°C | -3.2°C | 45 mm | 48% | 2.3 m/s | 4.8 |
| 2006 | 20.7°C | 13.2°C | 5.7°C | 29.3°C | -1.8°C | 52 mm | 51% | 1.8 m/s | 4.7 |
| 2005 | 20.9°C | 13.5°C | 6.0°C | 29.3°C | -0.3°C | 41 mm | 50% | 2.1 m/s | 4.8 |
| 2004 | 20.8°C | 13.4°C | 6.0°C | 29.6°C | -1.8°C | 41 mm | 51% | 2.1 m/s | 4.6 |
| 2003 | 22.3°C | 14.3°C | 6.3°C | 30.6°C | -1.4°C | 20 mm | 41% | 2.1 m/s | 5 |
| 2002 | 22.3°C | 14.8°C | 7.2°C | 31.9°C | 0.3°C | 45 mm | 45% | 2.2 m/s | 4.9 |
| 2001 | 25.0°C | 17.0°C | 8.9°C | 32.1°C | -0.4°C | 17 mm | 37% | 2.1 m/s | 5.3 |
| 2000 | 21.7°C | 13.8°C | 5.9°C | 32.5°C | -4.0°C | 26 mm | 43% | 2.3 m/s | 5.1 |
| 1999 | 21.0°C | 12.9°C | 4.7°C | 26.1°C | -4.7°C | 9 mm | 43% | 2 m/s | 5.6 |
| 1998 | 23.3°C | 16.4°C | 9.5°C | 30.6°C | 3.0°C | 47 mm | 53% | 1.7 m/s | 4.9 |
| 1997 | 21.5°C | 14.7°C | 7.9°C | 28.7°C | 0.8°C | 47 mm | 59% | 2.2 m/s | 5 |
| 1996 | 19.4°C | 12.0°C | 4.7°C | 28.4°C | -2.3°C | 36 mm | 49% | 2.1 m/s | 4.9 |
| 1995 | 21.8°C | 14.3°C | 6.9°C | 32.0°C | -4.7°C | 18 mm | 49% | 1.9 m/s | 5.3 |
| 1994 | 24.8°C | 16.7°C | 8.5°C | 30.8°C | 2.5°C | 28 mm | 33% | 2 m/s | 5.2 |
| 1993 | 20.3°C | 12.7°C | 5.0°C | 26.6°C | -0.1°C | 9 mm | 49% | 1.9 m/s | 5.2 |
| 1992 | 21.2°C | 13.2°C | 5.2°C | 27.1°C | -0.5°C | 25 mm | 42% | 2.3 m/s | 4.9 |
| 1991 | 21.7°C | 14.1°C | 6.5°C | 28.8°C | -1.0°C | 37 mm | 49% | 1.7 m/s | 4.9 |
| 1990 | 25.6°C | 17.7°C | 9.8°C | 31.5°C | 5.0°C | 21 mm | 41% | 1.7 m/s | 5.1 |
| 1989 | 22.3°C | 14.0°C | 5.7°C | 27.5°C | 0.6°C | 32 mm | 43% | 2.3 m/s | 5.4 |
| 1988 | 22.4°C | 13.8°C | 5.2°C | 32.6°C | -1.3°C | 11 mm | 38% | 2.4 m/s | 4.9 |
| 1987 | 24.4°C | 15.7°C | 6.9°C | 30.7°C | 0.5°C | 1 mm | 35% | 1.8 m/s | 5.5 |
| 1986 | 17.3°C | 10.8°C | 4.3°C | 26.2°C | -2.9°C | 42 mm | 58% | 2.1 m/s | 4.3 |
| 1985 ❄️ | 17.4°C | 10.1°C | 2.9°C | 25.5°C | -6.7°C | 65 mm | 53% | 2.5 m/s | 4.6 |
| 1984 | 19.3°C | 11.6°C | 4.0°C | 27.1°C | -4.4°C | 23 mm | 51% | 2.1 m/s | 4.7 |
| 1983 | 20.7°C | 13.3°C | 5.9°C | 30.3°C | -6.9°C | 63 mm | 53% | 2.3 m/s | — |
| 1982 | 20.1°C | 13.0°C | 5.8°C | 28.9°C | -1.4°C | 55 mm | 55% | 2.1 m/s | — |
| 1981 | 24.0°C | 15.9°C | 7.7°C | 30.4°C | -0.5°C | 12 mm | 37% | 2.2 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 22.1°C with lows near 6.9°C (mean 14.5°C), based on 45 years of NASA POWER data.
September averages 35 mm of rainfall in Rexburg, one of the drier months. The wettest on record was 87 mm in 2017.
The hottest September reached 35.3°C in 2022. The coldest dipped to -6.9°C in 1983.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 3.7°C. Daytime highs moved from 20.3°C to 24.1°C and overnight lows from 5.3°C to 9°C over the same span.
September is one of the warmer months of the year in Rexburg and one of the drier months, so plan for around 22.1°C daytime highs and 6.9°C at night.
Not quite — September is the 9th coolest month in Rexburg, averaging 14.5°C.
For September in Rexburg, pack warm layers and a jacket for chilly mornings, with typical highs of 22.1°C and lows of 6.9°C.
Relative humidity in September averages 48% — relatively dry.
Average wind speed in September is 2.1 m/s. The windiest September on record averaged 2.6 m/s (2013).
The wettest September on record was 2017 with 87 mm. On average, September sees 35 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 Rexburg 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.
