January is one of the cooler months of the year in Kailua, with average highs near 24°C and lows around 22.4°C (mean 23.2°C). It is a relatively wet time of year, averaging 67 mm of rainfall and 76% relative humidity across the period.
January is one of the cooler months of the year in Kailua. Across 45 years of records, the warmest January in Kailua was 2021 — when the month averaged 24.5°C — while the coldest were 1994 and 2000 at 22.1°C. Typical January days reach 24°C with nights near 22.4°C. The long-term trend is warming, about 0.3°C per decade.
January is a relatively wet time of year in Kailua, averaging 67 mm of rainfall. The wettest January on record was 1983 with 250 mm, while the driest was 2010 at 6 mm.
Relative humidity in Kailua during January averages 76%. The most humid January was 1984 at 81%, and the least humid was 1998 at 70%.
January receives about 4.1 kWh/m²/day of solar energy in Kailua. The sunniest Januarys were 2001, 2016 and 2022 at 4.5 kWh/m²/day, and the cloudiest was 1990 at 3.4.
Average wind speed in Kailua during January is 5 m/s. The windiest January was 2000 at 7 m/s, while the calmest was 2016 at 2.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 22.8°C | 22.7°C | 23.2°C | 23.4°C | 24.2°C | +1.4°C |
| Avg High | 23.5°C | 23.5°C | 24.0°C | 24.2°C | 25.0°C | +1.5°C |
| Avg Low | 22.1°C | 22.0°C | 22.5°C | 22.5°C | 23.3°C | +1.2°C |
| Avg Rain | 113 mm | 56 mm | 66 mm | 41 mm | 63 mm | -50 mm |
January temperatures in Kailua have risen by about 1.4°C between 1981–1985 and 2021–2025.
January has ranged from a record low of 18.9°C (1985) to a record high of 26.6°C (2021).
Rainfall in January is a relatively wet time of year, averaging 67 mm, with a wettest year of 250 mm.
A good time to visit Kailua
January is a good time to visit Kailua, with days averaging 24°C and nights around 22.4°C (mean 23.2°C, cooler than Kailua's yearly average) and moderate rainfall. February and April are marginally more temperate, but January still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 25.2°C | 24.3°C | 23.4°C | 26.4°C | 21.6°C | 43 mm | 75% | 4.8 m/s | 4.3 |
| 2024 | 25.1°C | 24.1°C | 23.2°C | 25.9°C | 20.0°C | 33 mm | 76% | 4.8 m/s | 4.2 |
| 2023 | 25.0°C | 24.1°C | 23.2°C | 26.2°C | 21.8°C | 62 mm | 77% | 3.9 m/s | 4.2 |
| 2022 | 24.8°C | 23.9°C | 23.0°C | 25.4°C | 21.9°C | 57 mm | 78% | 3.3 m/s | 4.5 |
| 2021 🔥 | 25.3°C | 24.5°C | 23.7°C | 26.6°C | 22.6°C | 93 mm | 76% | 6.2 m/s | 4.2 |
| 2020 | 24.8°C | 24.2°C | 23.5°C | 25.8°C | 22.4°C | 91 mm | 77% | 6.3 m/s | 4 |
| 2019 | 24.4°C | 23.5°C | 22.7°C | 25.6°C | 20.8°C | 36 mm | 74% | 5 m/s | 4.4 |
| 2018 | 24.2°C | 23.5°C | 22.7°C | 25.2°C | 22.0°C | 34 mm | 78% | 5.3 m/s | 4.4 |
| 2017 | 23.8°C | 23.1°C | 22.3°C | 25.3°C | 20.7°C | 18 mm | 75% | 4.6 m/s | 4.3 |
| 2016 | 25.0°C | 24.0°C | 23.1°C | 26.2°C | 22.4°C | 16 mm | 73% | 2.9 m/s | 4.5 |
| 2015 | 24.1°C | 23.1°C | 22.2°C | 25.6°C | 20.4°C | 38 mm | 74% | 3.7 m/s | 4.3 |
| 2014 | 24.2°C | 23.2°C | 22.3°C | 25.7°C | 20.5°C | 65 mm | 75% | 4.2 m/s | 4.3 |
| 2013 | 23.6°C | 22.8°C | 22.1°C | 25.0°C | 20.7°C | 73 mm | 78% | 5.6 m/s | 4.1 |
| 2012 | 24.3°C | 23.5°C | 22.7°C | 25.2°C | 21.9°C | 25 mm | 77% | 4.4 m/s | 4.4 |
| 2011 | 24.1°C | 23.3°C | 22.6°C | 25.1°C | 20.9°C | 98 mm | 74% | 4.6 m/s | 4.2 |
| 2010 | 24.4°C | 23.5°C | 22.6°C | 25.9°C | 21.0°C | 6 mm | 74% | 4.3 m/s | 4.3 |
| 2009 | 23.8°C | 23.0°C | 22.3°C | 25.3°C | 20.5°C | 33 mm | 75% | 5.4 m/s | 4.2 |
| 2008 | 23.6°C | 22.9°C | 22.3°C | 25.2°C | 21.0°C | 24 mm | 74% | 6.5 m/s | 4.3 |
| 2007 | 24.5°C | 23.8°C | 23.2°C | 25.2°C | 22.1°C | 34 mm | 75% | 6 m/s | 4.3 |
| 2006 | 24.3°C | 23.6°C | 22.9°C | 26.2°C | 21.6°C | 61 mm | 76% | 6.8 m/s | 4.3 |
| 2005 | 24.5°C | 23.5°C | 22.5°C | 25.3°C | 20.3°C | 122 mm | 79% | 4.5 m/s | 4 |
| 2004 | 24.4°C | 23.6°C | 22.8°C | 25.4°C | 21.4°C | 162 mm | 78% | 4.8 m/s | 4.1 |
| 2003 | 23.9°C | 22.9°C | 21.9°C | 25.6°C | 20.0°C | 56 mm | 73% | 4.9 m/s | 4.2 |
| 2002 | 23.8°C | 23.0°C | 22.3°C | 25.3°C | 21.2°C | 113 mm | 79% | 5.9 m/s | 4 |
| 2001 | 24.4°C | 23.6°C | 22.8°C | 25.5°C | 22.2°C | 25 mm | 76% | 5.5 m/s | 4.5 |
| 2000 | 22.7°C | 22.1°C | 21.5°C | 24.0°C | 20.4°C | 34 mm | 75% | 7 m/s | 4.2 |
| 1999 | 23.3°C | 22.6°C | 21.9°C | 24.7°C | 20.9°C | 36 mm | 78% | 5.9 m/s | 4.2 |
| 1998 | 23.9°C | 23.0°C | 22.2°C | 25.0°C | 20.5°C | 27 mm | 70% | 3.9 m/s | 4.1 |
| 1997 | 23.5°C | 22.6°C | 21.7°C | 25.2°C | 19.5°C | 53 mm | 78% | 5.1 m/s | 4 |
| 1996 | 24.4°C | 23.6°C | 22.8°C | 25.8°C | 20.7°C | 143 mm | 77% | 4.5 m/s | 3.9 |
| 1995 | 23.2°C | 22.5°C | 21.8°C | 24.9°C | 20.5°C | 23 mm | 74% | 5 m/s | 3.9 |
| 1994 ❄️ | 22.8°C | 22.1°C | 21.5°C | 24.6°C | 19.7°C | 35 mm | 74% | 5.4 m/s | 3.9 |
| 1993 | 23.3°C | 22.5°C | 21.6°C | 25.2°C | 20.5°C | 29 mm | 70% | 5.2 m/s | 3.8 |
| 1992 | 23.6°C | 22.8°C | 21.9°C | 24.7°C | 19.1°C | 30 mm | 72% | 4.3 m/s | 4.1 |
| 1991 | 23.2°C | 22.5°C | 21.8°C | 24.9°C | 19.8°C | 86 mm | 76% | 4.7 m/s | 4 |
| 1990 | 23.5°C | 22.9°C | 22.3°C | 25.0°C | 20.7°C | 93 mm | 79% | 6.3 m/s | 3.4 |
| 1989 | 23.8°C | 23.2°C | 22.6°C | 24.6°C | 21.5°C | 74 mm | 77% | 6.1 m/s | 3.9 |
| 1988 | 23.5°C | 22.9°C | 22.2°C | 25.1°C | 20.3°C | 86 mm | 79% | 5.2 m/s | 3.8 |
| 1987 | 23.2°C | 22.4°C | 21.7°C | 25.4°C | 19.7°C | 109 mm | 75% | 5.7 m/s | 3.6 |
| 1986 | 23.1°C | 22.4°C | 21.7°C | 24.7°C | 20.0°C | 52 mm | 77% | 4.6 m/s | 4 |
| 1985 | 23.2°C | 22.4°C | 21.5°C | 24.2°C | 18.9°C | 84 mm | 75% | 3.9 m/s | 3.9 |
| 1984 | 23.5°C | 22.9°C | 22.4°C | 24.5°C | 21.3°C | 150 mm | 81% | 5 m/s | 3.9 |
| 1983 🌧️ | 23.1°C | 22.4°C | 21.7°C | 24.0°C | 19.7°C | 250 mm | 76% | 4.4 m/s | — |
| 1982 | 23.5°C | 22.8°C | 22.2°C | 25.2°C | 19.6°C | 175 mm | 79% | 4.4 m/s | — |
| 1981 | 24.6°C | 23.7°C | 22.8°C | 25.9°C | 20.0°C | 36 mm | 75% | 3.8 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around 24°C with lows near 22.4°C (mean 23.2°C), based on 45 years of NASA POWER data.
January averages 67 mm of rainfall in Kailua, a relatively wet time of year. The wettest on record was 250 mm in 1983.
The hottest January reached 26.6°C in 2021. The coldest dipped to 18.9°C in 1985.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 1.4°C. Daytime highs moved from 23.6°C to 25.1°C and overnight lows from 22.1°C to 23.3°C over the same span.
January is one of the cooler months of the year in Kailua and a relatively wet time of year, so plan for around 24°C daytime highs and 22.4°C at night.
Not quite — January is the 3rd coolest month in Kailua, averaging 23.2°C.
For January in Kailua, pack light layers you can adjust through the day, with typical highs of 24°C and lows of 22.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in January averages 76% — quite humid.
Average wind speed in January is 5 m/s. The windiest January on record averaged 7 m/s (2000).
The wettest January on record was 1983 with 250 mm. On average, January sees 67 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 January, 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 January specifically, along with year-by-year records and how the month has changed over the decades.
