August is one of the warmer months of the year in El Cajon, with average highs near 33.3°C and lows around 18.1°C (mean 25.7°C). It is one of the drier months, averaging 10 mm of rainfall and 46% relative humidity across the period.
August is one of the warmer months of the year in El Cajon. Across 45 years of records, the warmest August in El Cajon was 2012 — when the month averaged 27.8°C — while the coldest was 1989 at 23.1°C. Typical August days reach 33.3°C with nights near 18.1°C. The long-term trend is warming, about 0.2°C per decade.
August is one of the drier months in El Cajon, averaging 10 mm of rainfall. The wettest August on record was 1983 with 66 mm, while the driest was 2002 at 0 mm.
Relative humidity in El Cajon during August averages 46%. The most humid August was 1983 at 56%, and the least humid was 1986 at 35%.
August receives about 7.1 kWh/m²/day of solar energy in El Cajon. The sunniest August was 2019 at 7.7 kWh/m²/day, and the cloudiest was 1984 at 6.
Average wind speed in El Cajon during August is 2.1 m/s. The windiest Augusts were 1989 and 2018 at 2.4 m/s, while the calmest were 1983, 1986 and 2012, among others at 1.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 25.4°C | 25.7°C | 25.5°C | 25.7°C | 26.5°C | +1.1°C |
| Avg High | 32.9°C | 33.3°C | 33.1°C | 33.3°C | 34.2°C | +1.3°C |
| Avg Low | 17.9°C | 18.2°C | 18.0°C | 18.1°C | 18.9°C | +1°C |
| Avg Rain | 17 mm | 8 mm | 7 mm | 7 mm | 16 mm | -1 mm |
August temperatures in El Cajon have risen by about 0.5°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 10°C (2010) to a record high of 42.4°C (2020).
Rainfall in August is one of the drier months, averaging 10 mm, with a wettest year of 66 mm.
A good time to visit El Cajon
August is a good time to visit El Cajon, with days averaging 33.3°C and nights around 18.1°C (mean 25.7°C, warmer than El Cajon's yearly average) and low rainfall. June and September are marginally more temperate, but August still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 34.3°C | 26.2°C | 18.0°C | 38.7°C | 12.7°C | 9 mm | 40% | 1.9 m/s | 7.1 |
| 2024 | 34.2°C | 26.4°C | 18.7°C | 40.8°C | 12.8°C | 5 mm | 42% | 2 m/s | 7.2 |
| 2023 | 32.9°C | 25.7°C | 18.4°C | 38.5°C | 13.8°C | 64 mm | 49% | 2.3 m/s | 6.9 |
| 2022 | 35.1°C | 27.7°C | 20.4°C | 40.9°C | 17.0°C | 9 mm | 44% | 2 m/s | 6.7 |
| 2021 | 33.6°C | 26.1°C | 18.7°C | 38.2°C | 14.3°C | 9 mm | 46% | 2.2 m/s | 7 |
| 2020 | 34.8°C | 27.0°C | 19.3°C | 42.4°C | 12.4°C | 0 mm | 42% | 2.2 m/s | 7.3 |
| 2019 | 33.9°C | 25.7°C | 17.5°C | 38.0°C | 13.8°C | 0 mm | 38% | 1.9 m/s | 7.7 |
| 2018 | 33.9°C | 26.4°C | 19.0°C | 39.4°C | 15.2°C | 4 mm | 49% | 2.4 m/s | 7.2 |
| 2017 | 33.5°C | 26.0°C | 18.5°C | 41.0°C | 13.3°C | 10 mm | 47% | 2 m/s | 7.3 |
| 2016 | 33.7°C | 25.7°C | 17.7°C | 39.1°C | 13.3°C | 1 mm | 45% | 2.2 m/s | 7.4 |
| 2015 | 33.3°C | 25.8°C | 18.3°C | 40.4°C | 13.3°C | 3 mm | 48% | 2.2 m/s | 7.3 |
| 2014 | 32.0°C | 24.7°C | 17.4°C | 37.0°C | 13.4°C | 20 mm | 53% | 2 m/s | 7.1 |
| 2013 | 32.0°C | 24.8°C | 17.5°C | 36.6°C | 11.6°C | 18 mm | 48% | 2.1 m/s | 7.1 |
| 2012 🔥 | 35.0°C | 27.8°C | 20.7°C | 40.1°C | 14.1°C | 10 mm | 46% | 1.8 m/s | 6.7 |
| 2011 | 33.5°C | 25.4°C | 17.3°C | 40.3°C | 12.8°C | 2 mm | 41% | 2.1 m/s | 7.5 |
| 2010 | 32.0°C | 24.3°C | 16.6°C | 40.4°C | 10.0°C | 1 mm | 43% | 2.2 m/s | 7.4 |
| 2009 | 33.5°C | 25.5°C | 17.5°C | 39.8°C | 12.5°C | 0 mm | 43% | 2.1 m/s | 7.4 |
| 2008 | 33.5°C | 26.0°C | 18.5°C | 37.0°C | 13.6°C | 9 mm | 46% | 2 m/s | 7 |
| 2007 | 34.0°C | 26.5°C | 19.0°C | 40.0°C | 13.7°C | 8 mm | 47% | 2 m/s | 7.1 |
| 2006 | 32.4°C | 24.8°C | 17.3°C | 37.9°C | 13.0°C | 1 mm | 48% | 2.2 m/s | 7.5 |
| 2005 | 32.8°C | 25.7°C | 18.6°C | 39.5°C | 13.6°C | 9 mm | 50% | 1.9 m/s | 7.1 |
| 2004 | 32.2°C | 24.5°C | 16.9°C | 38.5°C | 13.2°C | 2 mm | 50% | 2.2 m/s | 7.4 |
| 2003 | 33.8°C | 26.5°C | 19.2°C | 38.4°C | 15.3°C | 20 mm | 47% | 2.1 m/s | 6.9 |
| 2002 | 32.3°C | 24.1°C | 15.9°C | 38.9°C | 12.4°C | 0 mm | 47% | 2.1 m/s | 7.6 |
| 2001 | 33.4°C | 25.8°C | 18.1°C | 39.2°C | 13.0°C | 3 mm | 45% | 2 m/s | 7.4 |
| 2000 | 32.9°C | 25.9°C | 18.8°C | 38.6°C | 13.3°C | 15 mm | 47% | 2.1 m/s | 6.8 |
| 1999 | 32.7°C | 24.9°C | 17.0°C | 39.0°C | 11.7°C | 4 mm | 43% | 2.1 m/s | 7.4 |
| 1998 | 34.6°C | 27.3°C | 19.9°C | 40.6°C | 14.4°C | 10 mm | 46% | 1.9 m/s | 6.9 |
| 1997 | 33.3°C | 25.7°C | 18.1°C | 41.7°C | 13.9°C | 1 mm | 51% | 2.2 m/s | 7.1 |
| 1996 | 34.8°C | 26.9°C | 19.0°C | 39.8°C | 11.5°C | 1 mm | 44% | 2 m/s | 7.2 |
| 1995 | 34.8°C | 27.3°C | 19.7°C | 39.0°C | 15.2°C | 3 mm | 40% | 2.1 m/s | 6.9 |
| 1994 | 34.5°C | 27.0°C | 19.5°C | 41.0°C | 14.0°C | 10 mm | 45% | 2.1 m/s | 6.7 |
| 1993 | 31.5°C | 24.1°C | 16.8°C | 38.8°C | 12.4°C | 3 mm | 49% | 2 m/s | 7.2 |
| 1992 | 33.3°C | 26.3°C | 19.2°C | 37.6°C | 12.6°C | 26 mm | 51% | 1.9 m/s | 6.9 |
| 1991 | 31.0°C | 23.5°C | 15.9°C | 37.4°C | 10.9°C | 8 mm | 52% | 2.2 m/s | 7.2 |
| 1990 | 32.1°C | 24.3°C | 16.5°C | 38.0°C | 11.1°C | 7 mm | 51% | 2.1 m/s | 7.2 |
| 1989 ❄️ | 30.7°C | 23.1°C | 15.6°C | 35.3°C | 11.7°C | 3 mm | 54% | 2.4 m/s | 7.2 |
| 1988 | 32.0°C | 24.4°C | 16.7°C | 36.4°C | 11.8°C | 14 mm | 52% | 2.3 m/s | 6.9 |
| 1987 | 32.0°C | 24.4°C | 16.8°C | 37.6°C | 11.3°C | 8 mm | 48% | 2.2 m/s | 6.8 |
| 1986 | 34.8°C | 27.3°C | 19.8°C | 37.9°C | 15.6°C | 6 mm | 35% | 1.8 m/s | 7 |
| 1985 | 33.0°C | 25.0°C | 16.9°C | 41.4°C | 13.1°C | 0 mm | 40% | 2.2 m/s | 7.2 |
| 1984 | 32.9°C | 25.7°C | 18.5°C | 37.6°C | 14.7°C | 33 mm | 53% | 1.9 m/s | 6 |
| 1983 🌧️ | 32.3°C | 25.5°C | 18.7°C | 38.8°C | 12.2°C | 66 mm | 56% | 1.8 m/s | — |
| 1982 | 33.5°C | 26.3°C | 19.1°C | 38.2°C | 14.7°C | 14 mm | 40% | 1.8 m/s | — |
| 1981 | 34.8°C | 27.0°C | 19.2°C | 40.2°C | 13.1°C | 6 mm | 35% | 2.1 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 33.3°C with lows near 18.1°C (mean 25.7°C), based on 45 years of NASA POWER data.
August averages 10 mm of rainfall in El Cajon, one of the drier months. The wettest on record was 66 mm in 1983.
The hottest August reached 42.4°C in 2020. The coldest dipped to 10°C in 2010.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 0.5°C. Daytime highs moved from 33.3°C to 34°C and overnight lows from 18.5°C to 18.8°C over the same span.
August is one of the warmer months of the year in El Cajon and one of the drier months, so plan for around 33.3°C daytime highs and 18.1°C at night.
Not quite — August is the 12th coolest month in El Cajon, averaging 25.7°C.
For August in El Cajon, pack light, breathable clothing and sun protection, with typical highs of 33.3°C and lows of 18.1°C.
Relative humidity in August averages 46% — relatively dry.
Average wind speed in August is 2.1 m/s. The windiest August on record averaged 2.4 m/s (1989).
The wettest August on record was 1983 with 66 mm. On average, August sees 10 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 El Cajon behaves each August, 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 August specifically, along with year-by-year records and how the month has changed over the decades.
