October is one of the warmer months of the year in Simi Valley, with average highs near 26.3°C and lows around 11.1°C (mean 18.7°C). It is one of the drier months, averaging 17 mm of rainfall and 44% relative humidity across the period.
October is one of the warmer months of the year in Simi Valley. Across 45 years of records, the warmest Octobers in Simi Valley were 2020 and 2024 — when the month averaged 22.3°C — while the coldest was 1981 at 15.4°C. Typical October days reach 26.3°C with nights near 11.1°C. The long-term trend is warming, about 0.5°C per decade.
October is one of the drier months in Simi Valley, averaging 17 mm of rainfall. The wettest October on record was 2004 with 114 mm, while the driest were 1990, 2019 and 2020 at 0 mm.
Relative humidity in Simi Valley during October averages 44%. The most humid October was 2010 at 60%, and the least humid was 1999 at 26%.
October receives about 4.8 kWh/m²/day of solar energy in Simi Valley. The sunniest October was 2019 at 5.3 kWh/m²/day, and the cloudiest was 2010 at 4.
Average wind speed in Simi Valley during October is 2.1 m/s. The windiest October was 1984 at 3 m/s, while the calmest was 2002 at 1.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 17.5°C | 18.9°C | 18.2°C | 19.2°C | 20.2°C | +2.7°C |
| Avg High | 24.9°C | 26.7°C | 25.6°C | 26.7°C | 27.9°C | +3°C |
| Avg Low | 10.2°C | 11.1°C | 10.8°C | 11.7°C | 12.5°C | +2.3°C |
| Avg Rain | 17 mm | 12 mm | 27 mm | 12 mm | 13 mm | -5 mm |
October temperatures in Simi Valley have risen by about 3.2°C between 1981–1985 and 2021–2025.
October has ranged from a record low of 1.5°C (2009) to a record high of 40.4°C (2024).
Rainfall in October is one of the drier months, averaging 17 mm, with a wettest year of 114 mm.
One of the best times to visit Simi Valley
October is one of the best times to visit Simi Valley. Expect days averaging 26.3°C and nights around 11.1°C (mean 18.7°C) — warmer than Simi Valley's yearly average — with low rainfall (17 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 | 25.9°C | 18.4°C | 10.9°C | 30.5°C | 6.4°C | 46 mm | 57% | 2 m/s | 4.8 |
| 2024 | 30.3°C | 22.3°C | 14.4°C | 40.4°C | 5.4°C | 0 mm | 35% | 1.6 m/s | 4.8 |
| 2023 | 28.2°C | 20.4°C | 12.6°C | 35.1°C | 6.3°C | 1 mm | 40% | 2.2 m/s | 5 |
| 2022 | 28.2°C | 20.6°C | 12.9°C | 34.0°C | 6.3°C | 2 mm | 43% | 1.6 m/s | 4.7 |
| 2021 | 24.5°C | 17.2°C | 9.9°C | 32.9°C | 3.6°C | 26 mm | 48% | 2.2 m/s | 4.7 |
| 2020 🔥 | 30.5°C | 22.3°C | 14.1°C | 38.2°C | 6.7°C | 0 mm | 35% | 1.7 m/s | 4.8 |
| 2019 | 26.9°C | 18.7°C | 10.6°C | 33.3°C | 5.3°C | 0 mm | 30% | 2.6 m/s | 5.3 |
| 2018 | 26.4°C | 19.0°C | 11.6°C | 32.2°C | 7.8°C | 7 mm | 45% | 2 m/s | 4.8 |
| 2017 | 28.8°C | 20.4°C | 12.1°C | 34.5°C | 6.7°C | 0 mm | 32% | 2.3 m/s | 5.1 |
| 2016 | 26.0°C | 19.0°C | 11.9°C | 31.7°C | 8.0°C | 16 mm | 46% | 2.1 m/s | 4.7 |
| 2015 | 27.6°C | 21.1°C | 14.5°C | 35.5°C | 9.2°C | 11 mm | 51% | 1.9 m/s | 4.5 |
| 2014 | 28.7°C | 20.8°C | 12.8°C | 35.6°C | 7.3°C | 6 mm | 38% | 1.8 m/s | 5.1 |
| 2013 | 25.3°C | 17.2°C | 9.2°C | 30.0°C | 3.9°C | 3 mm | 40% | 2 m/s | 4.9 |
| 2012 | 26.9°C | 19.4°C | 11.8°C | 37.9°C | 5.2°C | 4 mm | 46% | 2.1 m/s | 4.8 |
| 2011 | 27.0°C | 19.0°C | 11.0°C | 34.5°C | 5.0°C | 22 mm | 45% | 2 m/s | 4.9 |
| 2010 | 23.8°C | 17.6°C | 11.4°C | 33.3°C | 5.8°C | 50 mm | 60% | 2.1 m/s | 4 |
| 2009 | 24.1°C | 16.7°C | 9.4°C | 31.7°C | 1.5°C | 47 mm | 51% | 2.5 m/s | 4.8 |
| 2008 | 28.0°C | 19.9°C | 11.9°C | 34.9°C | 2.8°C | 3 mm | 30% | 2.4 m/s | 5 |
| 2007 | 24.8°C | 17.5°C | 10.2°C | 31.6°C | 5.6°C | 9 mm | 45% | 2.6 m/s | 5 |
| 2006 | 24.2°C | 16.9°C | 9.5°C | 28.6°C | 6.1°C | 6 mm | 48% | 2.1 m/s | 4.8 |
| 2005 | 24.9°C | 17.5°C | 10.1°C | 32.2°C | 6.5°C | 42 mm | 51% | 2.2 m/s | 4.7 |
| 2004 🌧️ | 23.4°C | 16.7°C | 10.0°C | 33.3°C | 2.8°C | 114 mm | 58% | 2.2 m/s | 4.4 |
| 2003 | 30.2°C | 22.0°C | 13.9°C | 35.4°C | 5.4°C | 13 mm | 34% | 1.8 m/s | 5 |
| 2002 | 25.0°C | 17.4°C | 9.9°C | 33.9°C | 5.9°C | 2 mm | 48% | 1.4 m/s | 4.5 |
| 2001 | 28.0°C | 20.4°C | 12.9°C | 35.1°C | 7.7°C | 7 mm | 42% | 1.7 m/s | 4.7 |
| 2000 | 23.4°C | 16.8°C | 10.2°C | 31.8°C | 3.7°C | 27 mm | 58% | 2 m/s | 4.4 |
| 1999 | 29.6°C | 21.2°C | 12.9°C | 35.3°C | 7.9°C | 0 mm | 26% | 2.3 m/s | 5.2 |
| 1998 | 24.6°C | 16.9°C | 9.1°C | 28.7°C | 5.2°C | 4 mm | 42% | 2.2 m/s | 4.8 |
| 1997 | 25.8°C | 17.8°C | 9.8°C | 32.9°C | 5.1°C | 4 mm | 44% | 2.4 m/s | 5 |
| 1996 | 25.2°C | 17.7°C | 10.2°C | 36.1°C | 3.0°C | 44 mm | 41% | 2.6 m/s | 4.9 |
| 1995 | 27.8°C | 19.7°C | 11.6°C | 34.7°C | 6.7°C | 1 mm | 36% | 2 m/s | 4.9 |
| 1994 | 24.4°C | 16.9°C | 9.5°C | 29.5°C | 4.3°C | 21 mm | 46% | 2.1 m/s | 4.7 |
| 1993 | 26.1°C | 18.4°C | 10.8°C | 35.6°C | 5.4°C | 7 mm | 43% | 2 m/s | 4.7 |
| 1992 | 26.9°C | 19.5°C | 12.1°C | 33.2°C | 7.7°C | 30 mm | 47% | 1.9 m/s | 4.4 |
| 1991 | 28.2°C | 20.6°C | 13.1°C | 36.6°C | 2.2°C | 11 mm | 39% | 2.1 m/s | 4.7 |
| 1990 | 28.5°C | 20.0°C | 11.5°C | 33.3°C | 8.3°C | 0 mm | 31% | 2.1 m/s | 5 |
| 1989 | 24.6°C | 17.1°C | 9.6°C | 30.9°C | 3.8°C | 11 mm | 45% | 2.2 m/s | 4.8 |
| 1988 | 28.3°C | 20.4°C | 12.5°C | 33.6°C | 8.4°C | 0 mm | 39% | 1.8 m/s | 4.8 |
| 1987 | 26.7°C | 19.9°C | 13.1°C | 36.5°C | 8.3°C | 72 mm | 51% | 1.7 m/s | 4.4 |
| 1986 | 24.7°C | 17.2°C | 9.7°C | 29.5°C | 5.6°C | 3 mm | 41% | 2.1 m/s | 4.5 |
| 1985 | 25.4°C | 17.6°C | 9.9°C | 33.6°C | 4.0°C | 11 mm | 43% | 2.3 m/s | 4.8 |
| 1984 | 22.9°C | 15.6°C | 8.3°C | 30.8°C | 4.0°C | 5 mm | 47% | 3 m/s | 4.7 |
| 1983 | 24.4°C | 17.6°C | 10.9°C | 29.6°C | 7.6°C | 34 mm | 59% | 2.2 m/s | — |
| 1982 | 24.4°C | 16.9°C | 9.4°C | 29.6°C | 4.5°C | 12 mm | 40% | 2.4 m/s | — |
| 1981 ❄️ | 22.8°C | 15.4°C | 8.0°C | 29.3°C | 2.5°C | 9 mm | 46% | 2.4 m/s | — |
Actual recorded October data for each year, 1981–2025 — sourced from NASA POWER.
The average high in October is around 26.3°C with lows near 11.1°C (mean 18.7°C), based on 45 years of NASA POWER data.
October averages 17 mm of rainfall in Simi Valley, one of the drier months. The wettest on record was 114 mm in 2004.
The hottest October reached 40.4°C in 2024. The coldest dipped to 1.5°C in 2009.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average October temperatures have risen by about 3.2°C. Daytime highs moved from 24°C to 27.4°C and overnight lows from 9.3°C to 12.1°C over the same span.
October is one of the warmer months of the year in Simi Valley and one of the drier months, so plan for around 26.3°C daytime highs and 11.1°C at night.
Not quite — October is the 8th coolest month in Simi Valley, averaging 18.7°C.
For October in Simi Valley, pack light layers you can adjust through the day, with typical highs of 26.3°C and lows of 11.1°C.
Relative humidity in October averages 44% — relatively dry.
Average wind speed in October is 2.1 m/s. The windiest October on record averaged 3 m/s (1984).
The wettest October on record was 2004 with 114 mm. On average, October sees 17 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 Simi Valley behaves each October, 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 October specifically, along with year-by-year records and how the month has changed over the decades.
