July is one of the warmer months of the year in Simi Valley, with average highs near 34.9°C and lows around 17.4°C (mean 26.2°C). It is one of the drier months, averaging 2 mm of rainfall and 33% relative humidity across the period.
July is one of the warmer months of the year in Simi Valley. Across 45 years of records, the warmest July in Simi Valley was 2006 — when the month averaged 29.2°C — while the coldest was 1987 at 22.8°C. Typical July days reach 34.9°C with nights near 17.4°C. The long-term trend is warming, about 0.4°C per decade.
July is one of the drier months in Simi Valley, averaging 2 mm of rainfall. The wettest July on record was 2015 with 26 mm, while the driest were 2022, 2023 and 2025, among others at 0 mm.
Relative humidity in Simi Valley during July averages 33%. The most humid July was 2015 at 48%, and the least humid was 1981 at 21%.
July receives about 7.8 kWh/m²/day of solar energy in Simi Valley. The sunniest July was 2020 at 8.5 kWh/m²/day, and the cloudiest was 1988 at 7.
Average wind speed in Simi Valley during July is 1.9 m/s. The windiest Julys were 1989, 1992 and 2003, among others at 2.1 m/s, while the calmest were 2001, 2009 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 | 25.6°C | 25.4°C | 26.9°C | 26.2°C | 26.9°C | +1.3°C |
| Avg High | 34.5°C | 34.1°C | 35.7°C | 34.7°C | 35.5°C | +1°C |
| Avg Low | 16.8°C | 16.7°C | 18.1°C | 17.6°C | 18.3°C | +1.5°C |
| Avg Rain | 1 mm | 2 mm | 1 mm | 3 mm | 0 mm | -1 mm |
July temperatures in Simi Valley have risen by about 1.2°C between 1981–1985 and 2021–2025.
July has ranged from a record low of 9°C (1987) to a record high of 43.8°C (2024).
Rainfall in July is one of the drier months, averaging 2 mm, with a wettest year of 26 mm.
One of the best times to visit Simi Valley
July is one of the best times to visit Simi Valley. Expect days averaging 34.9°C and nights around 17.4°C (mean 26.2°C) — warmer than Simi Valley's yearly average — with low rainfall (2 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 | 33.7°C | 24.9°C | 16.0°C | 39.3°C | 13.0°C | 0 mm | 38% | 1.9 m/s | 8.2 |
| 2024 | 37.8°C | 29.1°C | 20.3°C | 43.8°C | 15.1°C | 0 mm | 26% | 1.8 m/s | 8 |
| 2023 | 36.2°C | 27.6°C | 19.0°C | 39.7°C | 12.4°C | 0 mm | 32% | 1.8 m/s | 8.1 |
| 2022 | 34.9°C | 26.6°C | 18.3°C | 38.9°C | 13.3°C | 0 mm | 33% | 1.9 m/s | 8 |
| 2021 | 35.7°C | 27.6°C | 19.4°C | 40.7°C | 15.2°C | 0 mm | 32% | 1.9 m/s | 7.7 |
| 2020 | 34.8°C | 25.6°C | 16.5°C | 39.8°C | 12.0°C | 0 mm | 32% | 1.9 m/s | 8.5 |
| 2019 | 34.7°C | 25.9°C | 17.0°C | 40.0°C | 12.3°C | 0 mm | 33% | 1.8 m/s | 8.1 |
| 2018 | 37.4°C | 29.0°C | 20.6°C | 42.7°C | 12.4°C | 0 mm | 33% | 1.9 m/s | 7.7 |
| 2017 | 36.7°C | 28.0°C | 19.3°C | 42.6°C | 14.0°C | 0 mm | 30% | 1.8 m/s | 8 |
| 2016 | 35.8°C | 26.5°C | 17.2°C | 41.2°C | 12.5°C | 0 mm | 29% | 2 m/s | 8.4 |
| 2015 🌧️ | 31.9°C | 24.1°C | 16.3°C | 35.4°C | 12.9°C | 26 mm | 48% | 1.9 m/s | 7.5 |
| 2014 | 34.6°C | 26.4°C | 18.1°C | 39.5°C | 14.3°C | 0 mm | 37% | 1.9 m/s | 7.7 |
| 2013 | 34.9°C | 26.6°C | 18.2°C | 39.2°C | 13.8°C | 1 mm | 33% | 1.9 m/s | 7.2 |
| 2012 | 33.1°C | 24.4°C | 15.8°C | 40.6°C | 10.0°C | 0 mm | 33% | 1.9 m/s | 8 |
| 2011 | 33.7°C | 25.1°C | 16.5°C | 37.4°C | 11.4°C | 1 mm | 37% | 1.7 m/s | 8 |
| 2010 | 34.7°C | 25.7°C | 16.6°C | 40.6°C | 13.0°C | 0 mm | 34% | 1.9 m/s | 8 |
| 2009 | 36.3°C | 27.5°C | 18.7°C | 40.4°C | 13.3°C | 0 mm | 27% | 1.7 m/s | 8.3 |
| 2008 | 35.5°C | 26.7°C | 17.9°C | 39.7°C | 14.6°C | 1 mm | 35% | 1.8 m/s | 7.9 |
| 2007 | 35.8°C | 26.8°C | 17.8°C | 41.1°C | 14.1°C | 0 mm | 32% | 1.9 m/s | 8 |
| 2006 🔥 | 37.4°C | 29.2°C | 21.0°C | 43.1°C | 16.0°C | 1 mm | 34% | 1.9 m/s | 7.7 |
| 2005 | 36.2°C | 27.6°C | 19.1°C | 40.8°C | 14.0°C | 1 mm | 37% | 1.8 m/s | 8 |
| 2004 | 35.0°C | 26.1°C | 17.1°C | 38.5°C | 13.0°C | 0 mm | 32% | 1.8 m/s | 8.2 |
| 2003 | 36.6°C | 27.8°C | 18.9°C | 40.2°C | 13.9°C | 5 mm | 31% | 2.1 m/s | 7.6 |
| 2002 | 35.5°C | 26.7°C | 17.9°C | 41.4°C | 13.6°C | 0 mm | 33% | 1.9 m/s | 8 |
| 2001 | 33.6°C | 25.1°C | 16.5°C | 39.7°C | 12.2°C | 3 mm | 38% | 1.7 m/s | 7.9 |
| 2000 | 34.7°C | 25.2°C | 15.7°C | 40.2°C | 10.7°C | 1 mm | 31% | 1.9 m/s | 8.1 |
| 1999 | 33.4°C | 25.1°C | 16.8°C | 36.0°C | 12.8°C | 7 mm | 34% | 1.9 m/s | 7.9 |
| 1998 | 33.8°C | 25.1°C | 16.4°C | 40.3°C | 10.9°C | 1 mm | 44% | 1.7 m/s | 8.3 |
| 1997 | 33.8°C | 24.8°C | 15.8°C | 39.9°C | 12.0°C | 1 mm | 36% | 2 m/s | 7.9 |
| 1996 | 36.3°C | 27.8°C | 19.3°C | 40.7°C | 14.1°C | 1 mm | 30% | 1.9 m/s | 8.1 |
| 1995 | 33.9°C | 25.2°C | 16.5°C | 42.3°C | 11.2°C | 1 mm | 37% | 1.9 m/s | 7.8 |
| 1994 | 35.3°C | 26.4°C | 17.4°C | 39.2°C | 13.4°C | 0 mm | 30% | 1.8 m/s | 7.8 |
| 1993 | 32.4°C | 23.3°C | 14.1°C | 37.5°C | 11.2°C | 0 mm | 43% | 1.9 m/s | 7.6 |
| 1992 | 32.7°C | 24.6°C | 16.4°C | 38.6°C | 10.1°C | 8 mm | 41% | 2.1 m/s | 7.2 |
| 1991 | 33.5°C | 24.7°C | 15.9°C | 39.1°C | 12.0°C | 1 mm | 37% | 1.8 m/s | 7.3 |
| 1990 | 35.7°C | 26.8°C | 18.0°C | 39.1°C | 13.6°C | 0 mm | 30% | 2 m/s | 8.1 |
| 1989 | 36.5°C | 26.9°C | 17.3°C | 41.9°C | 12.5°C | 0 mm | 26% | 2.1 m/s | 8.1 |
| 1988 | 35.8°C | 27.1°C | 18.3°C | 39.5°C | 13.2°C | 1 mm | 33% | 1.9 m/s | 7 |
| 1987 ❄️ | 32.0°C | 22.8°C | 13.6°C | 36.3°C | 9.0°C | 2 mm | 34% | 2 m/s | 7.5 |
| 1986 | 32.8°C | 24.2°C | 15.6°C | 37.4°C | 12.6°C | 2 mm | 33% | 2 m/s | 7.7 |
| 1985 | 36.2°C | 27.6°C | 19.0°C | 40.4°C | 13.5°C | 1 mm | 25% | 2.1 m/s | 7.4 |
| 1984 | 35.2°C | 27.2°C | 19.3°C | 39.8°C | 14.3°C | 6 mm | 32% | 1.9 m/s | 7.1 |
| 1983 | 32.4°C | 23.2°C | 14.1°C | 38.1°C | 9.5°C | 0 mm | 35% | 2.1 m/s | — |
| 1982 | 34.1°C | 25.3°C | 16.4°C | 40.1°C | 10.7°C | 0 mm | 29% | 1.9 m/s | — |
| 1981 | 35.5°C | 26.5°C | 17.5°C | 38.9°C | 14.5°C | 0 mm | 21% | 1.9 m/s | — |
Actual recorded July data for each year, 1981–2025 — sourced from NASA POWER.
The average high in July is around 34.9°C with lows near 17.4°C (mean 26.2°C), based on 45 years of NASA POWER data.
July averages 2 mm of rainfall in Simi Valley, one of the drier months. The wettest on record was 26 mm in 2015.
The hottest July reached 43.8°C in 2024. The coldest dipped to 9°C in 1987.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average July temperatures have risen by about 1.2°C. Daytime highs moved from 34.7°C to 35.7°C and overnight lows from 17.3°C to 18.6°C over the same span.
July is one of the warmer months of the year in Simi Valley and one of the drier months, so plan for around 34.9°C daytime highs and 17.4°C at night.
Not quite — July is the 11th coolest month in Simi Valley, averaging 26.2°C.
For July in Simi Valley, pack light, breathable clothing and sun protection, with typical highs of 34.9°C and lows of 17.4°C.
Relative humidity in July averages 33% — relatively dry.
Average wind speed in July is 1.9 m/s. The windiest July on record averaged 2.1 m/s (1983).
The wettest July on record was 2015 with 26 mm. On average, July sees 2 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 July, 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 July specifically, along with year-by-year records and how the month has changed over the decades.
