August is one of the warmer months of the year in Duncan, with average highs near 22.8°C and lows around 13.9°C (mean 18.4°C). It is one of the drier months, averaging 30 mm of rainfall and 72% relative humidity across the period.
August is one of the warmer months of the year in Duncan. Across 45 years of records, the warmest August in Duncan was 2022 — when the month averaged 20.7°C — while the coldest was 1995 at 15.8°C. Typical August days reach 22.8°C with nights near 13.9°C. The long-term trend is warming, about 0.6°C per decade.
August is one of the drier months in Duncan, averaging 30 mm of rainfall. The wettest August on record was 1991 with 123 mm, while the driest was 1986 at 2 mm.
Relative humidity in Duncan during August averages 72%. The most humid August was 1991 at 78%, and the least humid was 2003 at 66%.
August receives about 5.5 kWh/m²/day of solar energy in Duncan. The sunniest Augusts were 1998 and 2006 at 6.1 kWh/m²/day, and the cloudiest were 1991 and 1995 at 4.9.
Average wind speed in Duncan during August is 1.2 m/s. The windiest Augusts were 2015 and 2020 at 1.4 m/s, while the calmest were 1986, 1987 and 1990, among others at 1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 17.3°C | 18.1°C | 18.2°C | 19.3°C | 19.3°C | +2°C |
| Avg High | 21.9°C | 22.3°C | 22.7°C | 23.8°C | 23.8°C | +1.9°C |
| Avg Low | 12.7°C | 13.9°C | 13.7°C | 14.8°C | 14.8°C | +2.1°C |
| Avg Rain | 20 mm | 40 mm | 28 mm | 26 mm | 38 mm | +18 mm |
August temperatures in Duncan have risen by about 2.5°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 8.2°C (1982) to a record high of 35.4°C (2018).
Rainfall in August is one of the drier months, averaging 30 mm, with a wettest year of 123 mm.
One of the best times to visit Duncan
August is one of the best times to visit Duncan. Expect days averaging 22.8°C and nights around 13.9°C (mean 18.4°C) — warmer than Duncan's yearly average — with low rainfall (30 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 | 22.8°C | 18.6°C | 14.3°C | 29.8°C | 10.6°C | 52 mm | 77% | 1.3 m/s | 5.4 |
| 2024 | 23.4°C | 19.0°C | 14.6°C | 29.6°C | 10.4°C | 66 mm | 74% | 1.1 m/s | 5 |
| 2023 | 24.7°C | 19.8°C | 14.9°C | 30.6°C | 11.0°C | 31 mm | 70% | 1.3 m/s | 5.5 |
| 2022 🔥 | 25.3°C | 20.7°C | 16.1°C | 29.7°C | 12.6°C | 17 mm | 73% | 1.2 m/s | 6 |
| 2021 | 24.3°C | 19.7°C | 15.1°C | 32.8°C | 11.3°C | 16 mm | 69% | 1.3 m/s | 5.3 |
| 2020 | 22.4°C | 18.0°C | 13.6°C | 30.5°C | 10.6°C | 46 mm | 73% | 1.4 m/s | 5.9 |
| 2019 | 23.9°C | 19.5°C | 15.1°C | 29.7°C | 12.3°C | 26 mm | 71% | 1.2 m/s | 5.3 |
| 2018 | 24.8°C | 20.0°C | 15.2°C | 35.4°C | 12.2°C | 19 mm | 69% | 1.1 m/s | 5.3 |
| 2017 | 25.1°C | 20.3°C | 15.5°C | 29.6°C | 12.6°C | 16 mm | 72% | 1.2 m/s | 5.9 |
| 2016 | 23.9°C | 19.4°C | 14.8°C | 31.3°C | 12.7°C | 24 mm | 72% | 1.2 m/s | 5.8 |
| 2015 | 23.5°C | 19.1°C | 14.7°C | 28.9°C | 11.7°C | 43 mm | 70% | 1.4 m/s | 5.4 |
| 2014 | 25.0°C | 20.5°C | 15.9°C | 33.0°C | 12.6°C | 25 mm | 69% | 1.1 m/s | 5.5 |
| 2013 | 22.9°C | 18.8°C | 14.7°C | 28.5°C | 11.5°C | 52 mm | 76% | 1.1 m/s | 5 |
| 2012 | 23.4°C | 18.8°C | 14.3°C | 31.6°C | 10.8°C | 16 mm | 71% | 1.1 m/s | 5.5 |
| 2011 | 22.4°C | 18.0°C | 13.5°C | 26.6°C | 11.1°C | 13 mm | 73% | 1.1 m/s | 5.7 |
| 2010 | 23.5°C | 18.8°C | 14.2°C | 31.9°C | 9.8°C | 24 mm | 69% | 1.2 m/s | 5.4 |
| 2009 | 23.0°C | 18.3°C | 13.6°C | 31.5°C | 10.7°C | 23 mm | 70% | 1.1 m/s | 5.2 |
| 2008 | 22.1°C | 17.6°C | 13.1°C | 30.1°C | 9.4°C | 45 mm | 73% | 1.3 m/s | 5 |
| 2007 | 21.5°C | 17.5°C | 13.6°C | 27.1°C | 11.7°C | 19 mm | 73% | 1.2 m/s | 5.2 |
| 2006 | 22.7°C | 18.0°C | 13.3°C | 26.9°C | 11.3°C | 5 mm | 71% | 1.2 m/s | 6.1 |
| 2005 | 23.8°C | 19.2°C | 14.6°C | 29.1°C | 11.4°C | 19 mm | 71% | 1.1 m/s | 6 |
| 2004 | 24.3°C | 19.8°C | 15.3°C | 30.9°C | 12.8°C | 74 mm | 71% | 1.1 m/s | 5.2 |
| 2003 | 24.2°C | 19.2°C | 14.2°C | 28.9°C | 10.3°C | 8 mm | 66% | 1.2 m/s | 5.8 |
| 2002 | 23.0°C | 18.3°C | 13.6°C | 28.4°C | 10.6°C | 9 mm | 70% | 1.1 m/s | 5.9 |
| 2001 | 21.4°C | 17.4°C | 13.4°C | 28.9°C | 10.6°C | 66 mm | 77% | 1.2 m/s | 5 |
| 2000 | 20.9°C | 16.9°C | 12.8°C | 29.5°C | 9.8°C | 16 mm | 76% | 1.3 m/s | 5.7 |
| 1999 | 21.8°C | 17.9°C | 14.1°C | 26.1°C | 9.1°C | 43 mm | 78% | 1.2 m/s | 5.2 |
| 1998 | 23.4°C | 18.8°C | 14.3°C | 29.1°C | 11.8°C | 9 mm | 73% | 1.3 m/s | 6.1 |
| 1997 | 23.0°C | 19.0°C | 15.1°C | 29.7°C | 13.0°C | 54 mm | 75% | 1.1 m/s | 5.7 |
| 1996 | 21.8°C | 17.6°C | 13.3°C | 28.2°C | 10.7°C | 17 mm | 75% | 1.3 m/s | 5.5 |
| 1995 ❄️ | 19.5°C | 15.8°C | 12.2°C | 26.0°C | 10.0°C | 56 mm | 76% | 1.3 m/s | 4.9 |
| 1994 | 22.8°C | 18.5°C | 14.1°C | 27.8°C | 11.9°C | 25 mm | 70% | 1.2 m/s | 5.4 |
| 1993 | 22.4°C | 18.1°C | 13.8°C | 30.9°C | 10.4°C | 23 mm | 72% | 1.2 m/s | 5.1 |
| 1992 | 22.8°C | 18.2°C | 13.6°C | 29.6°C | 10.7°C | 23 mm | 71% | 1.1 m/s | 5.5 |
| 1991 🌧️ | 21.8°C | 17.8°C | 13.9°C | 27.3°C | 10.8°C | 123 mm | 78% | 1.2 m/s | 4.9 |
| 1990 | 23.3°C | 18.8°C | 14.2°C | 30.0°C | 10.4°C | 27 mm | 69% | 1 m/s | 5.2 |
| 1989 | 21.2°C | 16.9°C | 12.7°C | 25.5°C | 9.7°C | 44 mm | 76% | 1.1 m/s | 5.1 |
| 1988 | 21.6°C | 17.0°C | 12.4°C | 27.9°C | 10.0°C | 25 mm | 72% | 1.1 m/s | 5.3 |
| 1987 | 22.2°C | 17.2°C | 12.2°C | 29.2°C | 9.7°C | 13 mm | 72% | 1 m/s | 5.7 |
| 1986 | 24.1°C | 19.0°C | 13.9°C | 29.6°C | 10.5°C | 2 mm | 71% | 1 m/s | 5.8 |
| 1985 | 21.3°C | 16.6°C | 11.9°C | 27.3°C | 9.0°C | 22 mm | 70% | 1.1 m/s | 5.6 |
| 1984 | 20.5°C | 16.2°C | 11.9°C | 25.2°C | 9.3°C | 15 mm | 75% | 1.2 m/s | 5.3 |
| 1983 | 21.6°C | 17.2°C | 12.8°C | 24.6°C | 10.6°C | 21 mm | 74% | 1.1 m/s | — |
| 1982 | 20.8°C | 16.4°C | 12.1°C | 26.5°C | 8.2°C | 21 mm | 74% | 1.1 m/s | — |
| 1981 | 23.6°C | 19.0°C | 14.4°C | 33.6°C | 11.0°C | 20 mm | 73% | 1 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 22.8°C with lows near 13.9°C (mean 18.4°C), based on 45 years of NASA POWER data.
August averages 30 mm of rainfall in Duncan, one of the drier months. The wettest on record was 123 mm in 1991.
The hottest August reached 35.4°C in 2018. The coldest dipped to 8.2°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 2.5°C. Daytime highs moved from 21.6°C to 24.1°C and overnight lows from 12.6°C to 15°C over the same span.
August is one of the warmer months of the year in Duncan and one of the drier months, so plan for around 22.8°C daytime highs and 13.9°C at night.
Not quite — August is the 12th coolest month in Duncan, averaging 18.4°C.
For August in Duncan, pack light layers you can adjust through the day, with typical highs of 22.8°C and lows of 13.9°C.
Relative humidity in August averages 72% — moderately humid.
Average wind speed in August is 1.2 m/s. The windiest August on record averaged 1.4 m/s (2015).
The wettest August on record was 1991 with 123 mm. On average, August sees 30 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 Duncan 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.
