Kailua has a warm subtropical climate with warm summers and mild winters.
Temperatures peak in September and drop to their lowest in February, while rainfall is highest during winter months.
Humidity remains high throughout the year creating warm and humid conditions.
| Month | 🌤️ | Avg High | Avg Temp | Avg Low | Record High | Record Low | Humid % | Rain (mm) | Wind (m/s) | Solar (kWh/m²) |
|---|---|---|---|---|---|---|---|---|---|---|
| January | 🌞 | 75.1°F | 73.7°F | 72.3°F | 79.9°F | 66.0°F | 76% | 67 | 5.0 | 4.12 |
| February | 🌞 | 74.6°F | 73.1°F | 71.7°F | 79.9°F | 65.5°F | 75% | 63 | 5.3 | 4.84 |
| March | 🌞 | 74.8°F | 73.4°F | 72.0°F | 79.9°F | 66.0°F | 76% | 68 | 5.7 | 5.52 |
| April | 🌞 | 75.5°F | 74.1°F | 72.7°F | 80.6°F | 67.3°F | 77% | 45 | 6.1 | 6.19 |
| May | 🌞 | 76.8°F | 75.4°F | 74.0°F | 81.3°F | 66.9°F | 77% | 30 | 5.7 | 6.65 |
| June | 🌞 | 78.2°F | 76.9°F | 75.6°F | 83.5°F | 71.4°F | 77% | 20 | 6.4 | 6.98 |
| July | 🌞 | 79.1°F | 77.8°F | 76.6°F | 83.1°F | 73.2°F | 78% | 28 | 6.7 | 6.79 |
| August | 🌞 | 79.9°F | 78.6°F | 77.4°F | 84.6°F | 73.6°F | 77% | 34 | 6.4 | 6.63 |
| September | 🌞 | 80.2°F | 78.9°F | 77.6°F | 84.9°F | 73.6°F | 77% | 34 | 5.8 | 6.11 |
| October | 🌞 | 79.7°F | 78.4°F | 77.1°F | 84.2°F | 72.1°F | 77% | 52 | 5.5 | 5.17 |
| November | 🌞 | 78.1°F | 76.9°F | 75.7°F | 82.9°F | 69.1°F | 77% | 62 | 5.8 | 4.27 |
| December | 🌞 | 76.3°F | 75.0°F | 73.7°F | 80.8°F | 68.2°F | 76% | 71 | 5.5 | 3.87 |
Showing average climate conditions across 45 years (1981–2025)
🧥 Light layers are sufficient — this Mild Winter stays cool without prolonged hard freezes.
🌤️ Conditions are ideal for outdoor activities throughout the day in this Mild Summer.
☔ Rainfall is spread across the year with no sharply defined wet season.
Monthly averages · 1981–2025 climate normals · °F
Temperatures rise steadily from spring, peak in September, and gradually decline through autumn into winter.
These seasonal patterns offer comfortable conditions year-round, with warm summers and mild winters.
Monthly rainfall · 1981–2025 seasonal trends · mm/month
Rainfall is concentrated in the winter months. Humidity stays high (around 77%), peaking during summer months, which creates warm and humid conditions.
☔ Rainfall is spread across the year with no sharply defined wet season.
Monthly averages · 1981–2025
Across 45 years of records, Kailua's temperature shows a slight warming trend over the past decade. Its hottest day reached 85.0°F in September 2015, and its coldest dropped to 65.4°F in February 1981. 2025 was the warmest year overall and 1983 the coolest.
The warmest year in Kailua's recorded history was 2025 (avg: 78.1°F), while the coldest was 1983 (avg: 74.3°F).
Average annual high/low · Last 30 years · °F
Total annual precipitation · Last 30 years · mm/year
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall (mm) | Avg Humidity | Avg Wind |
|---|---|---|---|---|---|---|---|---|
2025 🔥 | 79.7°F | 78.1°F | 76.5°F | 83.3°F | 70.9°F | 266 | 76% | 5.4 m/s |
2024 | 78.6°F | 77.2°F | 75.6°F | 83.1°F | 68.0°F | 249 | 76% | 6.0 m/s |
2023 | 78.8°F | 77.4°F | 75.7°F | 82.8°F | 70.3°F | 441 | 77% | 5.7 m/s |
2022 | 78.8°F | 77.2°F | 75.7°F | 83.5°F | 71.1°F | 530 | 77% | 5.5 m/s |
2021 | 77.9°F | 76.6°F | 75.2°F | 81.5°F | 69.4°F | 834 | 77% | 6.1 m/s |
2020 | 78.8°F | 77.4°F | 76.1°F | 83.3°F | 68.9°F | 687 | 77% | 5.8 m/s |
2019 | 79.0°F | 77.5°F | 76.1°F | 84.6°F | 66.4°F | 690 | 77% | 5.5 m/s |
2018 | 77.7°F | 76.5°F | 75.2°F | 83.1°F | 68.5°F | 1006 | 80% | 5.6 m/s |
2017 | 78.3°F | 76.8°F | 75.4°F | 83.8°F | 67.3°F | 632 | 76% | 5.3 m/s |
2016 | 78.1°F | 76.8°F | 75.4°F | 82.6°F | 68.7°F | 603 | 77% | 5.6 m/s |
Showing 1 to 10 of 45 years
Based on 45 years of data (1981–2025), September is typically the hottest month in Kailua, Hawaii, with average high temperatures around 80.2°F.
February is the coldest month in Kailua, with average low temperatures around 71.7°F.
December receives the most rainfall with approximately 71 mm, while June is the driest with 20 mm.
The highest recorded temperature was 85.0°F in September 2015. This is part of the historical record spanning 1981–2025.
The lowest recorded temperature was 65.4°F in February 1981.
This page covers 45 years of climate data from 1981 to 2025. As new data is added to the database the page automatically reflects the updated coverage.
Kailua receives the most sunlight in June with an average solar radiation of 6.98 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning and agriculture in Hawaii.
All climate data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite and model data. It provides monthly averages for temperature, precipitation, humidity, wind speed, and solar radiation.
All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.
