September is one of the warmer months of the year in Roseville, with average highs near 32°C and lows around 15.6°C (mean 23.8°C). It is one of the drier months, averaging 11 mm of rainfall and 35% relative humidity across the period.
September is one of the warmer months of the year in Roseville. Across 45 years of records, the warmest September in Roseville was 2020 — when the month averaged 26.2°C — while the coldest was 1986 at 19°C. Typical September days reach 32°C with nights near 15.6°C. The long-term trend is warming, about 0.4°C per decade.
September is one of the drier months in Roseville, averaging 11 mm of rainfall. The wettest September on record was 1989 with 77 mm, while the driest were 2008, 2018 and 2020, among others at 0 mm.
Relative humidity in Roseville during September averages 35%. The most humid September was 1986 at 48%, and the least humid was 1988 at 25%.
September receives about 5.9 kWh/m²/day of solar energy in Roseville. The sunniest Septembers were 2008, 2016 and 2018, among others at 6.2 kWh/m²/day, and the cloudiest was 2020 at 5.3.
Average wind speed in Roseville during September is 1.5 m/s. The windiest Septembers were 2013 and 2016 at 1.7 m/s, while the calmest were 1991, 1993 and 1999, among others at 1.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 22.6°C | 23.8°C | 23.7°C | 24.1°C | 25.0°C | +2.4°C |
| Avg High | 30.6°C | 32.2°C | 32.1°C | 32.2°C | 33.0°C | +2.4°C |
| Avg Low | 14.5°C | 15.4°C | 15.4°C | 15.9°C | 17.0°C | +2.5°C |
| Avg Rain | 30 mm | 5 mm | 5 mm | 7 mm | 10 mm | -20 mm |
September temperatures in Roseville have risen by about 1.9°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 6.5°C (2019) to a record high of 46.6°C (2022).
Rainfall in September is one of the drier months, averaging 11 mm, with a wettest year of 77 mm.
One of the best times to visit Roseville
September is one of the best times to visit Roseville. Expect days averaging 32°C and nights around 15.6°C (mean 23.8°C) — warmer than Roseville's yearly average — with low rainfall (11 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 | 32.2°C | 24.7°C | 17.3°C | 41.0°C | 14.2°C | 8 mm | 44% | 1.5 m/s | 5.4 |
| 2024 | 34.0°C | 25.5°C | 17.0°C | 40.9°C | 11.9°C | 2 mm | 32% | 1.6 m/s | 6 |
| 2023 | 30.1°C | 22.5°C | 15.0°C | 35.8°C | 10.4°C | 13 mm | 47% | 1.5 m/s | 5.8 |
| 2022 | 33.5°C | 25.8°C | 18.1°C | 46.6°C | 13.0°C | 34 mm | 38% | 1.5 m/s | 5.6 |
| 2021 | 33.8°C | 25.2°C | 16.6°C | 41.7°C | 11.2°C | 6 mm | 31% | 1.6 m/s | 6 |
| 2020 🔥 | 34.4°C | 26.2°C | 18.0°C | 44.5°C | 13.9°C | 0 mm | 31% | 1.4 m/s | 5.3 |
| 2019 | 30.6°C | 22.9°C | 15.2°C | 39.2°C | 6.5°C | 24 mm | 42% | 1.6 m/s | 5.9 |
| 2018 | 32.2°C | 23.6°C | 15.0°C | 37.6°C | 9.4°C | 0 mm | 31% | 1.5 m/s | 6.2 |
| 2017 | 31.8°C | 24.4°C | 17.0°C | 43.7°C | 8.9°C | 4 mm | 38% | 1.5 m/s | 5.5 |
| 2016 | 31.9°C | 23.6°C | 15.3°C | 37.6°C | 10.1°C | 0 mm | 32% | 1.7 m/s | 6.2 |
| 2015 | 32.2°C | 24.5°C | 16.7°C | 40.9°C | 11.6°C | 3 mm | 31% | 1.6 m/s | 5.6 |
| 2014 | 32.1°C | 24.2°C | 16.3°C | 38.3°C | 11.4°C | 15 mm | 42% | 1.5 m/s | 5.9 |
| 2013 | 30.0°C | 22.4°C | 14.8°C | 38.6°C | 7.1°C | 20 mm | 45% | 1.7 m/s | 5.8 |
| 2012 | 34.3°C | 25.1°C | 15.9°C | 37.6°C | 10.9°C | 0 mm | 29% | 1.5 m/s | 6.1 |
| 2011 | 34.5°C | 26.0°C | 17.5°C | 40.8°C | 12.5°C | 1 mm | 32% | 1.5 m/s | 6 |
| 2010 | 32.1°C | 23.9°C | 15.6°C | 40.0°C | 10.3°C | 2 mm | 34% | 1.5 m/s | 6.1 |
| 2009 | 33.5°C | 25.3°C | 17.1°C | 39.8°C | 8.7°C | 6 mm | 32% | 1.4 m/s | 5.9 |
| 2008 | 33.4°C | 24.6°C | 15.7°C | 40.7°C | 10.4°C | 0 mm | 30% | 1.4 m/s | 6.2 |
| 2007 | 29.0°C | 21.4°C | 13.7°C | 39.1°C | 6.6°C | 12 mm | 44% | 1.6 m/s | 5.8 |
| 2006 | 31.9°C | 23.4°C | 14.9°C | 37.8°C | 9.8°C | 1 mm | 31% | 1.5 m/s | 6.1 |
| 2005 | 29.6°C | 21.5°C | 13.4°C | 35.4°C | 10.0°C | 3 mm | 38% | 1.5 m/s | 6.2 |
| 2004 | 32.1°C | 23.9°C | 15.7°C | 38.9°C | 8.6°C | 5 mm | 31% | 1.5 m/s | 6.2 |
| 2003 | 34.3°C | 25.6°C | 17.0°C | 40.9°C | 13.5°C | 1 mm | 32% | 1.6 m/s | 6.1 |
| 2002 | 33.0°C | 24.5°C | 16.1°C | 40.4°C | 10.0°C | 0 mm | 30% | 1.5 m/s | 6.1 |
| 2001 | 32.6°C | 24.1°C | 15.7°C | 38.6°C | 10.9°C | 10 mm | 37% | 1.5 m/s | 6 |
| 2000 | 31.3°C | 23.1°C | 14.9°C | 40.8°C | 9.2°C | 14 mm | 38% | 1.4 m/s | 5.8 |
| 1999 | 33.7°C | 24.7°C | 15.6°C | 37.4°C | 11.9°C | 2 mm | 29% | 1.3 m/s | 6.1 |
| 1998 | 31.4°C | 23.7°C | 16.1°C | 42.9°C | 10.6°C | 16 mm | 45% | 1.5 m/s | 5.7 |
| 1997 | 32.6°C | 24.2°C | 15.9°C | 37.5°C | 11.8°C | 6 mm | 36% | 1.5 m/s | 6 |
| 1996 | 30.8°C | 22.5°C | 14.1°C | 35.7°C | 9.8°C | 6 mm | 33% | 1.4 m/s | 6 |
| 1995 | 31.8°C | 23.5°C | 15.1°C | 38.4°C | 11.5°C | 0 mm | 36% | 1.4 m/s | 6.1 |
| 1994 | 31.4°C | 23.3°C | 15.1°C | 37.6°C | 10.5°C | 6 mm | 36% | 1.4 m/s | 5.7 |
| 1993 | 32.4°C | 23.9°C | 15.3°C | 38.7°C | 9.2°C | 3 mm | 31% | 1.3 m/s | 6.2 |
| 1992 | 32.2°C | 23.8°C | 15.4°C | 36.4°C | 12.2°C | 1 mm | 32% | 1.4 m/s | 6 |
| 1991 | 33.6°C | 25.0°C | 16.5°C | 39.1°C | 11.5°C | 1 mm | 31% | 1.3 m/s | 6.1 |
| 1990 | 32.2°C | 23.6°C | 15.0°C | 37.1°C | 11.5°C | 7 mm | 35% | 1.3 m/s | 6.1 |
| 1989 🌧️ | 29.0°C | 21.1°C | 13.2°C | 34.6°C | 9.1°C | 77 mm | 44% | 1.3 m/s | 5.7 |
| 1988 | 33.6°C | 24.6°C | 15.7°C | 44.9°C | 10.1°C | 1 mm | 25% | 1.4 m/s | 5.8 |
| 1987 | 33.2°C | 24.5°C | 15.7°C | 41.0°C | 11.1°C | 0 mm | 28% | 1.4 m/s | 5.9 |
| 1986 ❄️ | 26.2°C | 19.0°C | 11.7°C | 38.3°C | 6.9°C | 52 mm | 48% | 1.6 m/s | 5.7 |
| 1985 | 27.0°C | 19.6°C | 12.1°C | 34.6°C | 8.1°C | 35 mm | 46% | 1.4 m/s | 5.6 |
| 1984 | 33.4°C | 25.2°C | 16.9°C | 39.2°C | 9.8°C | 8 mm | 28% | 1.4 m/s | 5.6 |
| 1983 | 31.7°C | 23.7°C | 15.7°C | 38.4°C | 12.5°C | 29 mm | 39% | 1.4 m/s | — |
| 1982 | 29.1°C | 21.7°C | 14.4°C | 39.1°C | 7.1°C | 54 mm | 40% | 1.3 m/s | — |
| 1981 | 32.2°C | 23.8°C | 15.4°C | 37.3°C | 10.0°C | 17 mm | 33% | 1.5 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 32°C with lows near 15.6°C (mean 23.8°C), based on 45 years of NASA POWER data.
September averages 11 mm of rainfall in Roseville, one of the drier months. The wettest on record was 77 mm in 1989.
The hottest September reached 46.6°C in 2022. The coldest dipped to 6.5°C in 2019.
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 30.7°C to 32.7°C and overnight lows from 14.9°C to 16.8°C over the same span.
September is one of the warmer months of the year in Roseville and one of the drier months, so plan for around 32°C daytime highs and 15.6°C at night.
Not quite — September is the 10th coolest month in Roseville, averaging 23.8°C.
For September in Roseville, pack light, breathable clothing and sun protection, with typical highs of 32°C and lows of 15.6°C.
Relative humidity in September averages 35% — relatively dry.
Average wind speed in September is 1.5 m/s. The windiest September on record averaged 1.7 m/s (2013).
The wettest September on record was 1989 with 77 mm. On average, September sees 11 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 Roseville 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.
