August is one of the warmer months of the year in Johnstown, with average highs near 27.2°C and lows around 15°C (mean 21.1°C). It is about average for rainfall, averaging 93 mm of rainfall and 71% relative humidity across the period.
August is one of the warmer months of the year in Johnstown. Across 45 years of records, the warmest Augusts in Johnstown were 1995 and 2016 — when the month averaged 23.9°C — while the coldest were 1982 and 1992 at 18.8°C. Typical August days reach 27.2°C with nights near 15°C. The long-term trend is warming, about 0.3°C per decade.
August is about average for rainfall in Johnstown, averaging 93 mm of rainfall. The wettest August on record was 2024 with 185 mm, while the driest was 2025 at 26 mm.
Relative humidity in Johnstown during August averages 71%. The most humid August was 2018 at 84%, and the least humid was 2002 at 60%.
August receives about 5.1 kWh/m²/day of solar energy in Johnstown. The sunniest Augusts were 2008 and 2025 at 5.6 kWh/m²/day, and the cloudiest was 2000 at 4.5.
Average wind speed in Johnstown during August is 0.1 m/s. The windiest Augusts were 2023, 2024 and 2025, among others at 0.1 m/s, while the calmest was 2018 at 0 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 20.5°C | 20.7°C | 21.4°C | 21.1°C | 21.8°C | +1.3°C |
| Avg High | 26.8°C | 27.0°C | 27.4°C | 27.0°C | 27.8°C | +1°C |
| Avg Low | 14.2°C | 14.5°C | 15.4°C | 15.2°C | 15.8°C | +1.6°C |
| Avg Rain | 86 mm | 90 mm | 97 mm | 86 mm | 110 mm | +24 mm |
August temperatures in Johnstown have risen by about 1.3°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 2.5°C (1982) to a record high of 35.8°C (1988).
Rainfall in August is about average for rainfall, averaging 93 mm, with a wettest year of 185 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.2°C per decade while lows rose 0.4°C per decade, narrowing the gap between day and night.
One of the best times to visit Johnstown
August is one of the best times to visit Johnstown. Expect days averaging 27.2°C and nights around 15°C (mean 21.1°C) — warmer than Johnstown's yearly average — with higher rainfall (93 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 | 28.0°C | 21.0°C | 14.1°C | 34.1°C | 6.8°C | 26 mm | 61% | 0.1 m/s | 5.6 |
| 2024 🌧️ | 26.4°C | 20.8°C | 15.3°C | 31.7°C | 7.0°C | 185 mm | 78% | 0.1 m/s | 5 |
| 2023 | 26.9°C | 20.9°C | 14.9°C | 30.4°C | 9.3°C | 113 mm | 73% | 0.1 m/s | 5.2 |
| 2022 | 27.7°C | 21.9°C | 16.1°C | 33.2°C | 10.3°C | 128 mm | 73% | 0.1 m/s | 5.2 |
| 2021 | 28.9°C | 23.4°C | 17.9°C | 33.7°C | 11.1°C | 138 mm | 73% | 0.1 m/s | 4.8 |
| 2020 | 29.1°C | 22.8°C | 16.6°C | 34.0°C | 10.6°C | 70 mm | 66% | 0.1 m/s | 5.2 |
| 2019 | 26.5°C | 20.9°C | 15.3°C | 30.5°C | 9.1°C | 79 mm | 76% | 0.1 m/s | 5.3 |
| 2018 | 26.4°C | 21.6°C | 16.8°C | 30.3°C | 10.9°C | 121 mm | 84% | 0 m/s | 4.7 |
| 2017 | 25.7°C | 19.8°C | 14.0°C | 30.6°C | 9.3°C | 67 mm | 73% | 0.1 m/s | 5.1 |
| 2016 | 30.1°C | 23.9°C | 17.7°C | 33.3°C | 12.0°C | 87 mm | 69% | 0.1 m/s | 5.5 |
| 2015 | 27.2°C | 20.6°C | 13.9°C | 32.2°C | 9.5°C | 52 mm | 67% | 0.1 m/s | 5.5 |
| 2014 | 25.7°C | 19.6°C | 13.6°C | 30.2°C | 8.2°C | 110 mm | 75% | 0.1 m/s | 5.2 |
| 2013 | 26.2°C | 20.2°C | 14.2°C | 30.7°C | 8.0°C | 84 mm | 73% | 0.1 m/s | 5 |
| 2012 | 27.4°C | 21.4°C | 15.3°C | 32.0°C | 10.2°C | 69 mm | 68% | 0.1 m/s | 5.5 |
| 2011 | 26.2°C | 20.8°C | 15.3°C | 29.7°C | 9.3°C | 128 mm | 75% | 0.1 m/s | 5 |
| 2010 | 29.0°C | 22.6°C | 16.2°C | 33.2°C | 10.1°C | 65 mm | 66% | 0.1 m/s | 5.1 |
| 2009 | 26.9°C | 21.3°C | 15.7°C | 32.2°C | 9.4°C | 75 mm | 75% | 0.1 m/s | 5.1 |
| 2008 | 25.7°C | 19.3°C | 13.0°C | 31.4°C | 8.9°C | 73 mm | 70% | 0.1 m/s | 5.6 |
| 2007 | 27.4°C | 21.8°C | 16.2°C | 33.4°C | 10.6°C | 177 mm | 75% | 0.1 m/s | 4.8 |
| 2006 | 28.3°C | 21.9°C | 15.5°C | 32.8°C | 8.8°C | 88 mm | 66% | 0.1 m/s | 5.5 |
| 2005 | 29.2°C | 23.0°C | 16.7°C | 34.5°C | 10.9°C | 78 mm | 67% | 0.1 m/s | 4.8 |
| 2004 | 24.5°C | 19.2°C | 14.0°C | 29.4°C | 8.4°C | 102 mm | 81% | 0.1 m/s | 5.1 |
| 2003 | 26.7°C | 21.4°C | 16.1°C | 30.4°C | 8.5°C | 144 mm | 80% | 0.1 m/s | 4.9 |
| 2002 | 29.7°C | 22.8°C | 16.0°C | 35.0°C | 9.7°C | 57 mm | 60% | 0.1 m/s | 5.5 |
| 2001 | 29.7°C | 23.1°C | 16.4°C | 34.8°C | 11.8°C | 87 mm | 64% | 0.1 m/s | 5 |
| 2000 | 25.9°C | 20.1°C | 14.3°C | 29.0°C | 6.1°C | 85 mm | 71% | 0.1 m/s | 4.5 |
| 1999 | 27.6°C | 20.8°C | 14.0°C | 35.0°C | 7.8°C | 92 mm | 63% | 0.1 m/s | 5.2 |
| 1998 | 28.4°C | 21.8°C | 15.1°C | 32.0°C | 7.1°C | 68 mm | 66% | 0.1 m/s | 5.2 |
| 1997 | 25.7°C | 19.9°C | 14.1°C | 30.5°C | 9.1°C | 122 mm | 71% | 0.1 m/s | 4.8 |
| 1996 | 25.0°C | 19.4°C | 13.8°C | 29.3°C | 9.5°C | 83 mm | 79% | 0.1 m/s | 5.5 |
| 1995 🔥 | 31.0°C | 23.9°C | 16.8°C | 35.5°C | 10.6°C | 40 mm | 61% | 0.1 m/s | 5.3 |
| 1994 | 24.6°C | 18.9°C | 13.2°C | 29.8°C | 5.6°C | 180 mm | 78% | 0.1 m/s | 4.7 |
| 1993 | 28.6°C | 21.9°C | 15.2°C | 34.9°C | 8.9°C | 65 mm | 66% | 0.1 m/s | 5.3 |
| 1992 | 24.9°C | 18.8°C | 12.8°C | 29.7°C | 8.6°C | 78 mm | 73% | 0.1 m/s | 5.2 |
| 1991 | 28.8°C | 22.0°C | 15.2°C | 34.6°C | 10.7°C | 58 mm | 62% | 0.1 m/s | 5.2 |
| 1990 | 25.6°C | 20.0°C | 14.4°C | 31.7°C | 10.1°C | 112 mm | 76% | 0.1 m/s | 4.7 |
| 1989 | 24.4°C | 19.3°C | 14.1°C | 27.9°C | 8.5°C | 36 mm | 80% | 0.1 m/s | 4.9 |
| 1988 | 29.7°C | 22.9°C | 16.1°C | 35.8°C | 7.6°C | 105 mm | 61% | 0.1 m/s | 5 |
| 1987 | 27.3°C | 21.0°C | 14.6°C | 33.7°C | 7.0°C | 122 mm | 68% | 0.1 m/s | 4.8 |
| 1986 | 25.7°C | 19.4°C | 13.2°C | 29.6°C | 5.1°C | 65 mm | 68% | 0.1 m/s | 5.5 |
| 1985 | 26.5°C | 20.3°C | 14.2°C | 32.1°C | 10.3°C | 72 mm | 67% | 0.1 m/s | 4.7 |
| 1984 | 25.2°C | 19.9°C | 14.6°C | 30.4°C | 6.7°C | 166 mm | 82% | 0.1 m/s | 5.1 |
| 1983 | 29.6°C | 22.6°C | 15.6°C | 34.2°C | 8.8°C | 69 mm | 65% | 0.1 m/s | — |
| 1982 ❄️ | 25.4°C | 18.8°C | 12.2°C | 31.3°C | 2.5°C | 81 mm | 68% | 0.1 m/s | — |
| 1981 | 27.1°C | 20.1°C | 13.2°C | 30.5°C | 6.2°C | 60 mm | 65% | 0.1 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 27.2°C with lows near 15°C (mean 21.1°C), based on 45 years of NASA POWER data.
August averages 93 mm of rainfall in Johnstown, about average for rainfall. The wettest on record was 185 mm in 2024.
The hottest August reached 35.8°C in 1988. The coldest dipped to 2.5°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1.3°C. Daytime highs moved from 26.8°C to 27.6°C and overnight lows from 14°C to 15.7°C over the same span.
August is one of the warmer months of the year in Johnstown and about average for rainfall, so plan for around 27.2°C daytime highs and 15°C at night.
Not quite — August is the 11th coolest month in Johnstown, averaging 21.1°C.
For August in Johnstown, pack light layers you can adjust through the day, with typical highs of 27.2°C and lows of 15°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 71% — moderately humid.
Average wind speed in August is 0.1 m/s. The windiest August on record averaged 0.1 m/s (1981).
The wettest August on record was 2024 with 185 mm. On average, August sees 93 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 Johnstown 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.
