August is one of the warmer months of the year in Morristown, with average highs near 29.6°C and lows around 17.8°C (mean 23.7°C). It is about average for rainfall, averaging 101 mm of rainfall and 71% relative humidity across the period.
August is one of the warmer months of the year in Morristown. Across 45 years of records, the warmest August in Morristown was 2007 — when the month averaged 26.8°C — while the coldest was 1989 at 21.7°C. Typical August days reach 29.6°C with nights near 17.8°C. The long-term August temperature trend is broadly flat.
August is about average for rainfall in Morristown, averaging 101 mm of rainfall. The wettest August on record was 2021 with 220 mm, while the driest was 2007 at 40 mm.
Relative humidity in Morristown during August averages 71%. The most humid August was 2013 at 83%, and the least humid was 1999 at 58%.
August receives about 5.4 kWh/m²/day of solar energy in Morristown. The sunniest Augusts were 2011 and 2024 at 6.1 kWh/m²/day, and the cloudiest was 1985 at 4.5.
Average wind speed in Morristown during August is 0.5 m/s. The windiest Augusts were 1997, 1999 and 2000 at 0.6 m/s, while the calmest were 1996, 2003 and 2025 at 0.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 23.4°C | 23.5°C | 24.0°C | 23.8°C | 23.8°C | +0.4°C |
| Avg High | 29.4°C | 29.6°C | 30.0°C | 29.6°C | 29.4°C | 0°C |
| Avg Low | 17.5°C | 17.4°C | 18.0°C | 18.0°C | 18.2°C | +0.7°C |
| Avg Rain | 101 mm | 95 mm | 92 mm | 97 mm | 135 mm | +34 mm |
August temperatures in Morristown have risen by about 0.8°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 6.1°C (1986) to a record high of 38.8°C (1983).
Rainfall in August is about average for rainfall, averaging 101 mm, with a wettest year of 220 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0°C per decade while lows rose 0.2°C per decade, narrowing the gap between day and night.
One of the best times to visit Morristown
August is one of the best times to visit Morristown. Expect days averaging 29.6°C and nights around 17.8°C (mean 23.7°C) — warmer than Morristown's yearly average — with higher rainfall (101 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 | 29.2°C | 23.4°C | 17.5°C | 33.6°C | 11.2°C | 104 mm | 72% | 0.4 m/s | 5.5 |
| 2024 | 30.6°C | 24.1°C | 17.7°C | 35.2°C | 10.3°C | 70 mm | 68% | 0.5 m/s | 6.1 |
| 2023 | 29.0°C | 23.6°C | 18.3°C | 33.7°C | 13.0°C | 172 mm | 76% | 0.5 m/s | 5.2 |
| 2022 | 29.3°C | 23.9°C | 18.5°C | 33.3°C | 15.3°C | 93 mm | 76% | 0.5 m/s | 5.7 |
| 2021 🌧️ | 29.6°C | 24.3°C | 18.9°C | 33.7°C | 14.6°C | 220 mm | 74% | 0.5 m/s | 5.4 |
| 2020 | 28.8°C | 23.7°C | 18.5°C | 32.5°C | 16.4°C | 150 mm | 77% | 0.5 m/s | 5.4 |
| 2019 | 30.1°C | 24.4°C | 18.6°C | 33.3°C | 13.4°C | 84 mm | 71% | 0.5 m/s | 5.9 |
| 2018 | 29.0°C | 23.8°C | 18.6°C | 32.0°C | 11.7°C | 136 mm | 76% | 0.5 m/s | 5.2 |
| 2017 | 29.0°C | 23.2°C | 17.3°C | 33.6°C | 12.4°C | 116 mm | 71% | 0.5 m/s | 5.4 |
| 2016 | 31.5°C | 25.5°C | 19.6°C | 35.1°C | 13.9°C | 103 mm | 71% | 0.5 m/s | 5.6 |
| 2015 | 29.2°C | 23.1°C | 17.0°C | 31.9°C | 11.1°C | 78 mm | 70% | 0.5 m/s | 5.7 |
| 2014 | 28.9°C | 23.1°C | 17.4°C | 33.7°C | 12.9°C | 101 mm | 72% | 0.5 m/s | 5.4 |
| 2013 | 26.6°C | 21.8°C | 17.1°C | 30.1°C | 12.0°C | 101 mm | 83% | 0.5 m/s | 5.1 |
| 2012 | 29.1°C | 23.1°C | 17.0°C | 33.1°C | 12.9°C | 89 mm | 70% | 0.5 m/s | 5.6 |
| 2011 | 31.1°C | 24.5°C | 17.8°C | 34.6°C | 12.7°C | 51 mm | 66% | 0.5 m/s | 6.1 |
| 2010 | 31.4°C | 25.4°C | 19.5°C | 34.5°C | 14.8°C | 110 mm | 72% | 0.5 m/s | 5.8 |
| 2009 | 27.5°C | 22.3°C | 17.2°C | 30.4°C | 14.0°C | 112 mm | 79% | 0.5 m/s | 5.5 |
| 2008 | 30.1°C | 23.5°C | 16.9°C | 33.9°C | 11.5°C | 89 mm | 63% | 0.5 m/s | 5.8 |
| 2007 🔥 | 33.4°C | 26.8°C | 20.3°C | 37.2°C | 17.3°C | 40 mm | 59% | 0.5 m/s | 5.9 |
| 2006 | 31.3°C | 25.1°C | 19.0°C | 35.2°C | 14.7°C | 137 mm | 70% | 0.5 m/s | 5.3 |
| 2005 | 30.7°C | 24.9°C | 19.1°C | 33.8°C | 16.4°C | 103 mm | 70% | 0.5 m/s | 5.3 |
| 2004 | 28.3°C | 22.2°C | 16.2°C | 31.9°C | 9.6°C | 74 mm | 72% | 0.5 m/s | 5.4 |
| 2003 | 28.7°C | 23.7°C | 18.7°C | 33.2°C | 15.7°C | 118 mm | 79% | 0.4 m/s | 5.4 |
| 2002 | 31.9°C | 24.9°C | 17.9°C | 35.4°C | 12.7°C | 62 mm | 61% | 0.5 m/s | 5.8 |
| 2001 | 28.7°C | 23.2°C | 17.7°C | 31.8°C | 12.8°C | 113 mm | 74% | 0.5 m/s | 5.2 |
| 2000 | 29.6°C | 23.3°C | 17.0°C | 34.4°C | 13.4°C | 72 mm | 69% | 0.6 m/s | 5.4 |
| 1999 | 31.6°C | 24.1°C | 16.6°C | 35.0°C | 9.3°C | 41 mm | 58% | 0.6 m/s | 6 |
| 1998 | 30.5°C | 23.9°C | 17.2°C | 34.7°C | 12.6°C | 56 mm | 64% | 0.5 m/s | 5.8 |
| 1997 | 29.6°C | 23.0°C | 16.4°C | 33.2°C | 10.6°C | 47 mm | 65% | 0.6 m/s | 5.5 |
| 1996 | 28.4°C | 22.9°C | 17.4°C | 31.0°C | 15.0°C | 92 mm | 73% | 0.4 m/s | 5.5 |
| 1995 | 32.0°C | 25.9°C | 19.8°C | 37.2°C | 16.8°C | 100 mm | 67% | 0.5 m/s | 5.4 |
| 1994 | 27.6°C | 22.3°C | 17.1°C | 31.1°C | 12.8°C | 123 mm | 76% | 0.5 m/s | 5.1 |
| 1993 | 30.7°C | 24.5°C | 18.3°C | 34.6°C | 14.2°C | 111 mm | 68% | 0.5 m/s | 5.2 |
| 1992 | 27.5°C | 21.9°C | 16.3°C | 31.9°C | 10.5°C | 125 mm | 74% | 0.5 m/s | 4.7 |
| 1991 | 27.7°C | 22.5°C | 17.3°C | 31.0°C | 13.4°C | 140 mm | 78% | 0.5 m/s | 5.4 |
| 1990 | 30.3°C | 24.2°C | 18.0°C | 34.7°C | 15.1°C | 117 mm | 67% | 0.5 m/s | 5.1 |
| 1989 ❄️ | 26.8°C | 21.7°C | 16.7°C | 29.7°C | 7.7°C | 113 mm | 80% | 0.5 m/s | 5.2 |
| 1988 | 31.5°C | 25.1°C | 18.7°C | 36.8°C | 14.4°C | 111 mm | 65% | 0.5 m/s | 5.3 |
| 1987 | 32.2°C | 25.5°C | 18.8°C | 35.2°C | 13.6°C | 60 mm | 61% | 0.5 m/s | 5.2 |
| 1986 | 29.2°C | 23.1°C | 16.9°C | 33.9°C | 6.1°C | 138 mm | 69% | 0.5 m/s | 5 |
| 1985 | 27.7°C | 22.2°C | 16.8°C | 33.0°C | 12.4°C | 139 mm | 74% | 0.5 m/s | 4.5 |
| 1984 | 27.4°C | 22.2°C | 17.1°C | 29.3°C | 10.9°C | 70 mm | 77% | 0.5 m/s | 5 |
| 1983 | 32.3°C | 25.6°C | 19.0°C | 38.8°C | 12.8°C | 81 mm | 61% | 0.5 m/s | — |
| 1982 | 28.3°C | 22.4°C | 16.4°C | 31.9°C | 10.9°C | 116 mm | 74% | 0.5 m/s | — |
| 1981 | 29.3°C | 23.1°C | 16.8°C | 32.7°C | 11.7°C | 78 mm | 67% | 0.5 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 29.6°C with lows near 17.8°C (mean 23.7°C), based on 45 years of NASA POWER data.
August averages 101 mm of rainfall in Morristown, about average for rainfall. The wettest on record was 220 mm in 2021.
The hottest August reached 38.8°C in 1983. The coldest dipped to 6.1°C in 1986.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 0.8°C. Daytime highs moved from 29°C to 29.5°C and overnight lows from 17.2°C to 18.2°C over the same span.
August is one of the warmer months of the year in Morristown and about average for rainfall, so plan for around 29.6°C daytime highs and 17.8°C at night.
Not quite — August is the 11th coolest month in Morristown, averaging 23.7°C.
For August in Morristown, pack light layers you can adjust through the day, with typical highs of 29.6°C and lows of 17.8°C. Bring an umbrella or light rain jacket too.
Relative humidity in August averages 71% — moderately humid.
Average wind speed in August is 0.5 m/s. The windiest August on record averaged 0.6 m/s (1997).
The wettest August on record was 2021 with 220 mm. On average, August sees 101 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 Morristown 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.
