Climate and Average Weather Year Round in Kailua, Hawaii
Throughout the year, temperatures in Kailua range from 65°F to 84°F. Annual precipitation averages 48 inches. In Kailua, the air can feel uncomfortably humid during the summer months from May to December.
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Weather This Month
Climate of
Average Daily High Temperature
Note: Data is shown at the county level, which may not reflect city-level variation. Explore the USA climate map →
Best Time to Visit Kailua Based on Comfortable Weather
Every year, Kailua has about 132 days or 4.3 months with comfortable weather. The best time of year to visit Kailua is January to April.
The number of days per year with comfortable weather are calculated using the following criteria, which favor mild temperatures and low humidity:
- Daily high temperatures between 65ºF and 86ºF (18°C and 30°C)
- Daily maximum dew point temperatures less than or equal to 65ºF (18°C)
- Average daily cloud cover less than or equal to 65%
- Average daily wind speed less than or equal to 18 mph (5.8 m/s)
Average Temperature in Kailua
In the summer months, the hottest month of the year in Kailua is September, with an average high of 84°F and average low of 73°F. In the winter months, the lowest temperatures are reached in the month of January with an average high of 78°F and average low of 65°F.
Average Temperatures by Month in Kailua
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| High | 78°F | 77°F | 78°F | 79°F | 81°F | 82°F | 83°F | 84°F | 84°F | 83°F | 81°F | 78°F |
| Average | 72°F | 72°F | 72°F | 74°F | 75°F | 77°F | 78°F | 79°F | 79°F | 77°F | 75°F | 73°F |
| Low | 65°F | 66°F | 67°F | 68°F | 70°F | 72°F | 73°F | 73°F | 73°F | 72°F | 70°F | 68°F |
Precipitation
Kailua receives an annual precipitation of 48 inches. Precipitation includes rain and liquid equivalent of snow, hail, freezing rain, sleet. Month with most precipitation in Kailua is March, with an average monthly precipitation of 6 inches.
Average Monthly Total Precipitation in Kailua
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Precipitation | 4.6" | 5.2" | 6.2" | 3.7" | 2.7" | 2.0" | 2.5" | 3.0" | 3.6" | 4.6" | 5.2" | 5.1" |
Snowfall
Kailua does not receive significant snowfall (greater than 1 inch).
Average Monthly Total Snowfall in Kailua
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Snowfall | 0.0" | 0.0" | 0.0" | 0.0" | 0.0" | 0.0" | 0.0" | 0.0" | 0.0" | 0.0" | 0.0" | 0.0" |
Humidity
We use dew point to measure humidity comfort since it shows whether sweat can evaporate from our skin to cool us -
lower dew points feel drier and higher ones feel more humid. When sweat evaporates, it draws heat from our skin,
which is how our bodies naturally cool down.
Generally, if the dew point temperature is below 50ºF, humidity levels make the air feel dry.
If the dew point temperature is between 50-60ºF, moisture levels are comfortable.
When the dew point temperature exceeds 60ºF, the air will feel noticeably humid.
If the dew point temperature climbs to 70ºF or higher, the air will feel muggy and unpleasantly uncomfortable.
In Kailua, the air can feel uncomfortably humid during the summer months from May to December.
This occurs when dewpoint temperature is above 65ºF.
Average Monthly Humidity in Kailua
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dewpoint Temperature | 64°F | 63°F | 64°F | 65°F | 66°F | 68°F | 69°F | 69°F | 69°F | 69°F | 67°F | 65°F |
Wind Speed
In Kailua, the wind speed remains relatively consistent throughout the year, with an average of 9 mph in the winter months (January, February, March, and December). In the summer months (June, July, and August), the average wind speed changes to 10 mph. Overall, the variation in wind speed ranges between 8.0 mph and 11.0 mph across the months.
Average Monthly Wind speed in Kailua
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind Speed | 8 | 9 | 9 | 10 | 9 | 10 | 11 | 10 | 9 | 9 | 9 | 9 |
Cloud Cover
In Kailua, the month with the clearest sky, characterized by predominantly clear, few, and scattered clouds, is September, when the sky is clear or has few and scattered clouds 68.0% of the time. The cloudiest month of the year in Kailua is April, when the sky is overcast or covered with broken clouds, occurring 43.0% of the time.
Average Monthly Cloud Cover in Kailua
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clear Sky (%) | 63 | 63 | 59 | 58 | 63 | 63 | 61 | 66 | 68 | 65 | 61 | 63 |
| Cloudier Sky (%) | 37 | 37 | 41 | 42 | 37 | 37 | 39 | 34 | 32 | 35 | 39 | 37 |
Sun
In Kailua, the longest day of the year is June 21 with about 13 hr 26 min 3 sec of daylight.
The shortest day in Kailua falls on December 21 with about 10 hr 49 min 25 sec of daylight.
How this is calculated: Based on the location’s latitude and longitude, we determine the local time zone and calculate daily sunrise and sunset times using a solar position algorithm. The difference between sunset and sunrise gives the day length. Repeating this process for every day of the year allows us to identify the longest and shortest days for that location.
Sunshine Hours
In Kailua, the month with most sunshine hours is June (10.1 hrs), and the month with least sunshine hours is December (6.9 hrs). Total annual sunshine hours: 3138.3 hrs.
In everyday terms, this represents the average amount of daily sunlight a location receives — often described as "hours of sun per day," "average daily sunlight," "sunshine duration," or "sunlight daily". These measures all capture how bright and sunny a place really feels across the seasons.
Tracking sunshine hours and sunny days can also highlight areas with limited daylight, which is especially important for people managing Seasonal Affective Disorder (SAD). This information is also a practical guide when comparing climates, planning a move, choosing a vacation spot, or avoiding long, gloomy winters.
In the chart below, each day is represented as a 24-hour cycle, divided into sunshine hours, cloudy daylight hours, and night. For example, if a location had 10 hours of daylight and 6 of those were sunny, the chart would show 6 hours of sunshine, 4 hours of cloudy daylight, and the remaining 14 hours as night.
Average Monthly Sunshine Hours in Kailua
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunshine (hrs) | 7.2 | 7.4 | 7.6 | 8.4 | 9.2 | 10.1 | 10.1 | 10.0 | 9.8 | 8.4 | 7.4 | 6.9 |
Sunshine Percentage
In Kailua, the month with most sunshine percentage is September (80.8%), and the month with least sunshine percentage is March (63.7%).
Sunshine percentage is calculated by comparing the actual sunshine hours in a day to the maximum possible daylight hours (based on the sun’s position at that longitude/latitude and time of year). For example, if a location had 6 hours of sunshine during a 10-hour day, the sunshine percentage would be 60%. This gives an easy-to-understand measure of how much of the available daylight was truly sunny.
Unlike cloud cover data, which represent average conditions over the full 24-hour day (including night), sunshine percentage looks only at the daylight hours. This makes it a more practical measure for everyday use — whether it’s tracking seasonal changes in sunlight to manage Seasonal Affective Disorder (SAD), planning outdoor activities, choosing travel destinations, or simply finding places that avoid long stretches of gloomy weather.
Average Monthly Sunshine Percentage in Kailua
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunshine (%) | 66.7 | 66.0 | 63.7 | 67.5 | 70.7 | 76.6 | 77.2 | 79.4 | 80.8 | 73.5 | 67.5 | 64.6 |
Solar Energy
In Kailua, the month with most solar energy is June (6.7 kWh/m²), and the month with least solar energy is December (3.6 kWh/m²). Total annual solar energy for Kailua is 1979.4 kWh/m².
Solar energy here refers to the total shortwave radiation (sunlight) reaching the ground, measured as Global Horizontal Irradiance (GHI). It combines both direct and diffuse sunlight scattered by the atmosphere. Hourly GHI values are converted into daily energy (in kWh/m²) by summing the radiation over each day.
In everyday terms, GHI reflects the total amount of sunlight energy available at a location — a measure often used to understand seasonal changes in daily sunlight, compare how sunny different places are, or evaluate solar power potential.
Average Monthly Solar Energy in Kailua
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar Energy (kWh/m²) | 3.9 | 4.5 | 5.1 | 5.9 | 6.3 | 6.7 | 6.6 | 6.5 | 6.1 | 5.0 | 4.0 | 3.6 |
Kailua
County: Honolulu
State: Hawaii
Population: 106,260
Annual Temperature Range: 65°F in January to 84°F in September
Annual Precipitation: 48 inches
Annual Snowfall: 0 inches
Number of Comfortable Weather Days: 132 or 4.3 months
Annual Sunshine: 3138.3 hours
Annual Solar Energy: 1979.4 kWh/m²
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Data Sources
myPerfectWeather.com uses data from the National Center for Environmental Information, with 15,000+ weather stations across the USA reporting precipitation, snowfall, humidity and temperature. The data is collected and processed over a 30-year period from 1991-2020, ensuring accuracy. A sophisticated algorithm identifies nearby weather stations for each city and calculates weather data based on a weighted average of station data, ensuring accuracy and relevance. To view the weather stations used in the calculations, simply click on the '' icon on the map. We also source population information from the US Census database and use industry-leading technology from © OpenStreetMap and Leaflet to power our maps. With these powerful tools, you can easily visualize and explore weather patterns in your area with confidence and accuracy.
The GHI and DNI data come from the U.S. National Renewable Energy Laboratory (NREL), which uses its Physical Solar Model (PSM) together with satellite observations from the GOES weather satellites. The model first calculates the theoretical amount of solar radiation based on the Sun’s position for a given location and time. It then adjusts those values using satellite measurements of real-world conditions — such as clouds, haze, smoke, and aerosols — that block or scatter sunlight. To highlight reliable patterns rather than day-to-day weather noise, the results are averaged over many years.
Sunshine hours (or Sunshine duration) per day are estimated by counting the time when direct sunlight (measured as Direct Normal Irradiance, or DNI) exceeds 120 W/m², following the World Meteorological Organization standard. Sunshine hours are calculated only during daylight and are averaged over many years to capture long-term patterns.
Climate data shown on the map is currently at the county level for performance reasons. In geographically diverse regions (such as San Diego County), this may not accurately reflect conditions in specific cities or neighborhoods.
Disclaimer
The information displayed in the visualizations on this website is provided without warranty of any kind, either expressed or implied, including without limitation, any warranty of accuracy, reliability, or suitability for any particular purpose. The weather data used in the visualizations is obtained from external sources and may contain errors resulting from factors such as equipment failures, complex data processing procedures, transmission issues, geospatial mapping to specific counties, and other defects not explicitly mentioned here. The website's creators assume no liability for any damages or losses arising from the use of the information presented on this site or for any decisions made based on such information.