August is one of the warmer months of the year in Modesto, with average highs near 36.2°C and lows around 14.9°C (mean 25.6°C). It is one of the drier months, averaging 1 mm of rainfall and 43% relative humidity across the period.
August is one of the warmer months of the year in Modesto. Across 45 years of records, the warmest August in Modesto was 2020 — when the month averaged 27.5°C — while the coldest was 2010 at 23.5°C. Typical August days reach 36.2°C with nights near 14.9°C. The long-term trend is warming, about 0.3°C per decade.
August is one of the drier months in Modesto, averaging 1 mm of rainfall. The wettest August on record was 2003 with 8 mm, while the driest were 2018, 2019 and 2021, among others at 0 mm.
Relative humidity in Modesto during August averages 43%. The most humid August was 1991 at 51%, and the least humid was 1986 at 37%.
August receives about 7.3 kWh/m²/day of solar energy in Modesto. The sunniest August was 1998 at 7.9 kWh/m²/day, and the cloudiest was 1984 at 6.6.
Average wind speed in Modesto during August is 2.7 m/s. The windiest August was 2025 at 3 m/s, while the calmest was 1986 at 2.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 25.1°C | 25.4°C | 25.4°C | 25.6°C | 26.7°C | +1.6°C |
| Avg High | 35.8°C | 35.9°C | 36.1°C | 36.3°C | 37.2°C | +1.4°C |
| Avg Low | 14.4°C | 14.8°C | 14.7°C | 14.9°C | 16.0°C | +1.6°C |
| Avg Rain | 1 mm | 1 mm | 1 mm | 0 mm | 1 mm | 0 mm |
August temperatures in Modesto have risen by about 1.5°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 9.9°C (2009) to a record high of 45.9°C (1998).
Rainfall in August is one of the drier months, averaging 1 mm, with a wettest year of 8 mm.
One of the best times to visit Modesto
August is one of the best times to visit Modesto. Expect days averaging 36.2°C and nights around 14.9°C (mean 25.6°C) — warmer than Modesto's yearly average — with low rainfall (1 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 | 37.2°C | 26.3°C | 15.4°C | 41.6°C | 12.3°C | 2 mm | 43% | 3 m/s | 7.3 |
| 2024 | 36.3°C | 26.0°C | 15.6°C | 44.1°C | 12.5°C | 0 mm | 42% | 2.9 m/s | 7.1 |
| 2023 | 37.1°C | 26.8°C | 16.6°C | 42.2°C | 12.2°C | 1 mm | 42% | 2.8 m/s | 7 |
| 2022 | 38.2°C | 27.2°C | 16.1°C | 43.6°C | 13.5°C | 0 mm | 40% | 2.8 m/s | 7.1 |
| 2021 | 37.0°C | 26.1°C | 15.2°C | 41.8°C | 11.6°C | 0 mm | 41% | 2.8 m/s | 7.1 |
| 2020 🔥 | 37.6°C | 27.5°C | 17.3°C | 43.6°C | 12.8°C | 0 mm | 39% | 2.8 m/s | 6.8 |
| 2019 | 37.0°C | 26.6°C | 16.3°C | 42.8°C | 13.0°C | 0 mm | 42% | 2.9 m/s | 7.5 |
| 2018 | 36.3°C | 25.5°C | 14.7°C | 42.6°C | 11.2°C | 0 mm | 42% | 2.8 m/s | 7.3 |
| 2017 | 37.5°C | 27.3°C | 17.0°C | 44.3°C | 12.0°C | 0 mm | 40% | 2.8 m/s | 6.9 |
| 2016 | 36.7°C | 25.5°C | 14.3°C | 41.4°C | 11.4°C | 0 mm | 42% | 2.8 m/s | 7.5 |
| 2015 | 35.7°C | 25.7°C | 15.7°C | 42.1°C | 13.3°C | 1 mm | 47% | 2.8 m/s | 7.3 |
| 2014 | 35.8°C | 25.7°C | 15.5°C | 42.1°C | 12.7°C | 0 mm | 47% | 2.7 m/s | 7.1 |
| 2013 | 35.0°C | 24.7°C | 14.3°C | 41.1°C | 11.3°C | 0 mm | 50% | 2.9 m/s | 7.5 |
| 2012 | 38.1°C | 26.6°C | 15.1°C | 44.9°C | 9.9°C | 0 mm | 38% | 2.9 m/s | 7.4 |
| 2011 | 36.2°C | 24.8°C | 13.4°C | 39.5°C | 11.1°C | 0 mm | 46% | 2.9 m/s | 7.7 |
| 2010 ❄️ | 34.5°C | 23.5°C | 12.6°C | 44.8°C | 9.9°C | 0 mm | 48% | 2.8 m/s | 7.7 |
| 2009 | 35.8°C | 25.1°C | 14.4°C | 41.3°C | 9.9°C | 0 mm | 44% | 2.8 m/s | 7.3 |
| 2008 | 37.0°C | 26.0°C | 15.0°C | 42.5°C | 11.2°C | 0 mm | 43% | 2.9 m/s | 7.5 |
| 2007 | 36.3°C | 25.6°C | 14.9°C | 41.8°C | 11.0°C | 0 mm | 45% | 2.8 m/s | 7.5 |
| 2006 | 35.5°C | 24.6°C | 13.8°C | 40.0°C | 10.6°C | 0 mm | 45% | 2.5 m/s | 7.7 |
| 2005 | 37.3°C | 26.6°C | 15.9°C | 42.1°C | 12.1°C | 1 mm | 40% | 2.6 m/s | 7.4 |
| 2004 | 36.0°C | 25.5°C | 15.0°C | 43.1°C | 11.3°C | 2 mm | 47% | 2.7 m/s | 7.4 |
| 2003 🌧️ | 35.4°C | 25.2°C | 15.0°C | 40.5°C | 11.7°C | 8 mm | 48% | 2.7 m/s | 7.3 |
| 2002 | 35.6°C | 24.7°C | 13.8°C | 41.6°C | 10.1°C | 1 mm | 43% | 2.7 m/s | 7.5 |
| 2001 | 36.1°C | 25.2°C | 14.3°C | 43.0°C | 11.6°C | 0 mm | 47% | 2.9 m/s | 7.6 |
| 2000 | 36.0°C | 25.3°C | 14.5°C | 43.5°C | 10.7°C | 2 mm | 43% | 2.7 m/s | 7.4 |
| 1999 | 33.7°C | 23.7°C | 13.8°C | 42.1°C | 11.0°C | 1 mm | 48% | 2.7 m/s | 7.3 |
| 1998 | 38.2°C | 27.0°C | 15.8°C | 45.9°C | 11.1°C | 0 mm | 38% | 2.6 m/s | 7.9 |
| 1997 | 35.4°C | 25.3°C | 15.1°C | 45.7°C | 12.8°C | 7 mm | 48% | 2.8 m/s | 7.5 |
| 1996 | 37.9°C | 26.7°C | 15.4°C | 44.5°C | 10.5°C | 2 mm | 37% | 2.6 m/s | 7.5 |
| 1995 | 36.3°C | 25.5°C | 14.7°C | 41.9°C | 10.3°C | 0 mm | 39% | 2.6 m/s | 7.8 |
| 1994 | 37.0°C | 25.4°C | 13.9°C | 41.8°C | 11.5°C | 0 mm | 42% | 2.8 m/s | 7.3 |
| 1993 | 34.9°C | 24.8°C | 14.6°C | 42.4°C | 11.7°C | 0 mm | 44% | 2.6 m/s | 7.3 |
| 1992 | 37.1°C | 26.4°C | 15.7°C | 42.1°C | 11.2°C | 0 mm | 39% | 2.8 m/s | 7.2 |
| 1991 | 33.8°C | 23.7°C | 13.6°C | 38.3°C | 11.3°C | 3 mm | 51% | 2.8 m/s | 7.3 |
| 1990 | 34.8°C | 25.1°C | 15.3°C | 44.5°C | 11.4°C | 0 mm | 45% | 2.8 m/s | 7.3 |
| 1989 | 34.5°C | 23.7°C | 13.0°C | 39.4°C | 10.3°C | 1 mm | 44% | 2.5 m/s | 7.3 |
| 1988 | 36.5°C | 25.8°C | 15.2°C | 41.4°C | 10.9°C | 0 mm | 41% | 2.7 m/s | 7.2 |
| 1987 | 36.4°C | 25.3°C | 14.2°C | 41.6°C | 10.0°C | 0 mm | 38% | 2.4 m/s | 7.2 |
| 1986 | 37.3°C | 25.9°C | 14.6°C | 40.7°C | 12.0°C | 0 mm | 37% | 2.3 m/s | 7.1 |
| 1985 | 34.4°C | 24.0°C | 13.6°C | 38.6°C | 11.2°C | 0 mm | 40% | 2.7 m/s | 7.2 |
| 1984 | 36.1°C | 25.4°C | 14.7°C | 42.2°C | 11.2°C | 1 mm | 41% | 2.8 m/s | 6.6 |
| 1983 | 35.0°C | 25.2°C | 15.5°C | 43.0°C | 11.7°C | 7 mm | 45% | 2.6 m/s | — |
| 1982 | 34.9°C | 24.7°C | 14.5°C | 41.0°C | 11.4°C | 0 mm | 41% | 2.8 m/s | — |
| 1981 | 37.0°C | 25.6°C | 14.2°C | 42.8°C | 11.3°C | 0 mm | 40% | 2.9 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 36.2°C with lows near 14.9°C (mean 25.6°C), based on 45 years of NASA POWER data.
August averages 1 mm of rainfall in Modesto, one of the drier months. The wettest on record was 8 mm in 2003.
The hottest August reached 45.9°C in 1998. The coldest dipped to 9.9°C in 2009.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1.5°C. Daytime highs moved from 35.5°C to 37.2°C and overnight lows from 14.5°C to 15.8°C over the same span.
August is one of the warmer months of the year in Modesto and one of the drier months, so plan for around 36.2°C daytime highs and 14.9°C at night.
Not quite — August is the 11th coolest month in Modesto, averaging 25.6°C.
For August in Modesto, pack light, breathable clothing and sun protection, with typical highs of 36.2°C and lows of 14.9°C.
Relative humidity in August averages 43% — relatively dry.
Average wind speed in August is 2.7 m/s. The windiest August on record averaged 3 m/s (2025).
The wettest August on record was 2003 with 8 mm. On average, August sees 1 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 Modesto 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.
