August is one of the warmer months of the year in Kailua, with average highs near 26.6°C and lows around 25.2°C (mean 25.9°C). It is one of the drier months, averaging 34 mm of rainfall and 77% relative humidity across the period.
August is one of the warmer months of the year in Kailua. Across 45 years of records, the warmest August in Kailua was 2019 — when the month averaged 27.4°C — while the coldest was 1983 at 24.7°C. Typical August days reach 26.6°C with nights near 25.2°C. The long-term trend is warming, about 0.3°C per decade.
August is one of the drier months in Kailua, averaging 34 mm of rainfall. The wettest August on record was 1983 with 189 mm, while the driest was 2023 at 5 mm.
Relative humidity in Kailua during August averages 77%. The most humid August was 1982 at 82%, and the least humid was 2005 at 74%.
August receives about 6.6 kWh/m²/day of solar energy in Kailua. The sunniest Augusts were 2005, 2022 and 2023, among others at 7.1 kWh/m²/day, and the cloudiest was 1986 at 5.8.
Average wind speed in Kailua during August is 6.4 m/s. The windiest August was 1999 at 7.2 m/s, while the calmest was 2015 at 4.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 25.5°C | 25.7°C | 25.9°C | 26.2°C | 26.4°C | +0.9°C |
| Avg High | 26.1°C | 26.3°C | 26.6°C | 26.9°C | 27.2°C | +1.1°C |
| Avg Low | 24.8°C | 25.1°C | 25.2°C | 25.5°C | 25.6°C | +0.8°C |
| Avg Rain | 63 mm | 15 mm | 28 mm | 41 mm | 21 mm | -41 mm |
August temperatures in Kailua have risen by about 1.2°C between 1981–1985 and 2021–2025.
August has ranged from a record low of 23.1°C (1999) to a record high of 29.2°C (2015).
Rainfall in August is one of the drier months, averaging 34 mm, with a wettest year of 189 mm.
A quieter season to visit Kailua
If your dates are flexible, the more temperate months of February and April tend to be the most comfortable for visiting Kailua. That said, August — with days averaging 26.6°C and nights around 25.2°C (mean 25.9°C) and moderate rainfall (34 mm) — can still be rewarding for travellers who don't mind the warmth, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 27.7°C | 26.8°C | 25.9°C | 28.3°C | 25.3°C | 7 mm | 75% | 5.9 m/s | 6.8 |
| 2024 | 27.2°C | 26.4°C | 25.7°C | 28.2°C | 24.8°C | 20 mm | 79% | 6.6 m/s | 6.6 |
| 2023 | 27.2°C | 26.4°C | 25.6°C | 27.8°C | 24.6°C | 5 mm | 75% | 6.9 m/s | 7.1 |
| 2022 | 27.4°C | 26.5°C | 25.6°C | 28.4°C | 24.9°C | 37 mm | 77% | 5.7 m/s | 7.1 |
| 2021 | 26.7°C | 25.9°C | 25.1°C | 27.5°C | 24.5°C | 37 mm | 77% | 6.3 m/s | 7 |
| 2020 | 27.2°C | 26.4°C | 25.7°C | 27.9°C | 25.1°C | 21 mm | 77% | 6.5 m/s | 7 |
| 2019 🔥 | 28.1°C | 27.4°C | 26.6°C | 28.9°C | 26.1°C | 27 mm | 78% | 5.6 m/s | 6.9 |
| 2018 | 26.9°C | 26.3°C | 25.7°C | 28.0°C | 25.0°C | 85 mm | 80% | 7 m/s | 5.9 |
| 2017 | 27.3°C | 26.6°C | 25.9°C | 27.9°C | 25.4°C | 29 mm | 76% | 6.3 m/s | 6.9 |
| 2016 | 27.0°C | 26.4°C | 25.8°C | 28.0°C | 25.2°C | 73 mm | 80% | 6.3 m/s | 6.5 |
| 2015 | 28.0°C | 27.3°C | 26.6°C | 29.2°C | 25.8°C | 111 mm | 80% | 4.8 m/s | 6.4 |
| 2014 | 27.2°C | 26.4°C | 25.7°C | 27.8°C | 25.3°C | 32 mm | 77% | 6 m/s | 6.7 |
| 2013 | 26.9°C | 26.0°C | 25.2°C | 27.8°C | 24.7°C | 28 mm | 76% | 6.3 m/s | 7 |
| 2012 | 25.9°C | 25.1°C | 24.4°C | 27.2°C | 23.9°C | 16 mm | 77% | 6.6 m/s | 6.9 |
| 2011 | 26.0°C | 25.3°C | 24.6°C | 26.6°C | 24.3°C | 7 mm | 76% | 6.7 m/s | 6.7 |
| 2010 | 26.0°C | 25.4°C | 24.7°C | 26.6°C | 24.2°C | 6 mm | 76% | 6.7 m/s | 6.8 |
| 2009 | 26.7°C | 26.0°C | 25.3°C | 27.3°C | 24.9°C | 22 mm | 77% | 6.6 m/s | 6.6 |
| 2008 | 26.5°C | 25.7°C | 25.0°C | 27.0°C | 24.3°C | 22 mm | 76% | 6.6 m/s | 6.9 |
| 2007 | 26.7°C | 26.0°C | 25.2°C | 27.7°C | 24.7°C | 8 mm | 76% | 6.5 m/s | 6.9 |
| 2006 | 26.7°C | 26.0°C | 25.3°C | 28.1°C | 24.5°C | 24 mm | 76% | 6.2 m/s | 6.7 |
| 2005 | 26.7°C | 26.0°C | 25.3°C | 27.5°C | 24.7°C | 17 mm | 74% | 6.1 m/s | 7.1 |
| 2004 | 27.4°C | 26.7°C | 26.0°C | 28.4°C | 25.5°C | 67 mm | 78% | 6.4 m/s | 6.5 |
| 2003 | 26.6°C | 25.9°C | 25.2°C | 27.5°C | 24.6°C | 17 mm | 77% | 7.1 m/s | 6.8 |
| 2002 | 26.3°C | 25.7°C | 25.0°C | 27.0°C | 24.3°C | 48 mm | 80% | 6.5 m/s | 6.2 |
| 2001 | 26.2°C | 25.6°C | 25.0°C | 27.5°C | 24.4°C | 22 mm | 78% | 7.1 m/s | 6.4 |
| 2000 | 26.0°C | 25.3°C | 24.6°C | 27.3°C | 24.1°C | 29 mm | 76% | 6.8 m/s | 6.8 |
| 1999 | 25.8°C | 25.1°C | 24.5°C | 26.3°C | 23.1°C | 8 mm | 76% | 7.2 m/s | 6.8 |
| 1998 | 26.0°C | 25.4°C | 24.8°C | 27.2°C | 23.4°C | 10 mm | 75% | 6.7 m/s | 6.6 |
| 1997 | 26.7°C | 26.0°C | 25.3°C | 27.6°C | 24.1°C | 11 mm | 76% | 5.8 m/s | 6.9 |
| 1996 | 27.1°C | 26.3°C | 25.6°C | 28.2°C | 24.7°C | 11 mm | 76% | 5.8 m/s | 7.1 |
| 1995 | 26.2°C | 25.6°C | 25.0°C | 26.7°C | 24.6°C | 11 mm | 76% | 7 m/s | 6.6 |
| 1994 | 26.7°C | 26.0°C | 25.4°C | 27.2°C | 24.7°C | 17 mm | 77% | 6.7 m/s | 6.3 |
| 1993 | 26.4°C | 25.7°C | 25.0°C | 27.2°C | 24.3°C | 11 mm | 78% | 6.2 m/s | 6.3 |
| 1992 | 26.3°C | 25.8°C | 25.2°C | 27.0°C | 24.7°C | 17 mm | 78% | 7.1 m/s | 6 |
| 1991 | 26.0°C | 25.4°C | 24.8°C | 27.2°C | 23.8°C | 34 mm | 80% | 6.6 m/s | 6.1 |
| 1990 | 26.1°C | 25.5°C | 24.9°C | 27.0°C | 24.2°C | 18 mm | 79% | 6.3 m/s | 6.4 |
| 1989 | 26.1°C | 25.4°C | 24.6°C | 27.0°C | 23.7°C | 23 mm | 77% | 6 m/s | 6.3 |
| 1988 | 26.2°C | 25.5°C | 24.8°C | 27.0°C | 24.2°C | 37 mm | 77% | 6.4 m/s | 6.7 |
| 1987 | 27.0°C | 26.2°C | 25.4°C | 28.7°C | 24.7°C | 16 mm | 75% | 5.5 m/s | 6.7 |
| 1986 | 26.7°C | 26.0°C | 25.4°C | 27.6°C | 24.3°C | 46 mm | 81% | 6.1 m/s | 5.8 |
| 1985 | 26.0°C | 25.2°C | 24.5°C | 27.7°C | 23.7°C | 52 mm | 79% | 6 m/s | 6.3 |
| 1984 | 25.8°C | 25.1°C | 24.4°C | 26.7°C | 23.8°C | 29 mm | 78% | 5.9 m/s | 6.5 |
| 1983 ❄️ 🌧️ | 25.3°C | 24.7°C | 24.0°C | 26.5°C | 23.3°C | 189 mm | 80% | 6.4 m/s | — |
| 1982 | 26.0°C | 25.5°C | 24.9°C | 26.4°C | 24.1°C | 133 mm | 82% | 6.7 m/s | — |
| 1981 | 26.2°C | 25.5°C | 24.9°C | 26.6°C | 24.5°C | 39 mm | 80% | 5.8 m/s | — |
Actual recorded August data for each year, 1981–2025 — sourced from NASA POWER.
The average high in August is around 26.6°C with lows near 25.2°C (mean 25.9°C), based on 45 years of NASA POWER data.
August averages 34 mm of rainfall in Kailua, one of the drier months. The wettest on record was 189 mm in 1983.
The hottest August reached 29.2°C in 2015. The coldest dipped to 23.1°C in 1999.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average August temperatures have risen by about 1.2°C. Daytime highs moved from 25.9°C to 27.2°C and overnight lows from 24.5°C to 25.6°C over the same span.
August is one of the warmer months of the year in Kailua and one of the drier months, so plan for around 26.6°C daytime highs and 25.2°C at night.
Not quite — August is the 11th coolest month in Kailua, averaging 25.9°C.
For August in Kailua, pack light layers you can adjust through the day, with typical highs of 26.6°C and lows of 25.2°C.
Relative humidity in August averages 77% — quite humid.
Average wind speed in August is 6.4 m/s. The windiest August on record averaged 7.2 m/s (1999).
The wettest August on record was 1983 with 189 mm. On average, August sees 34 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 Kailua 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.
