Climate and monthly weather forecastWailuku, HI
Climate and monthly weather forecast
The climate of Wailuku
Wailuku, Hawaii sits within a climatic zone known as As, according to the Köppen climate classification. This is a tropical wet and dry climate, often referred to as a savanna climate. Positioned within the tropics, Wailuku experiences warm temperatures all year round and relative humidity consistently around 75%. It is characterized by a distinct wet and dry seasonality, without any cold winter.Analyzing the climate data for Wailuku, it reveals that the tropical location results in small temperature fluctuations throughout the year. Peak temperature in the warmest month reaches 79.9°F (26.6°C), whilst in cooler months it usually stays above 70.7°F (21.5°C). Isn't that a paradise-like climate for most of us from colder parts of the world?
Rainfall varies from a low of 0.2" (5mm) during peak summer up to 0.87" (22mm) in the cooler months, with more rainfall days registered from March to May and again in December. The dry season is typically from June through to September with almost half the amount of rainfall compared to the wet season.
UV index is constant at 6 from November through April, while reaching a peak at 7 from May to October. Wind speed generally sits between 10.4mph (16.7km/h) and 13.6mph (21.9km/h). Highest recorded monthly average for wind gusts is 18.6mph (29.9km/h) from June to August.
The best time to visit Wailuku
It's always pleasant in Wailuku, but if prefered outdoor activity is dependent on the sunniest days, the best time to visit would be from May to September. These months offer up to 11 hours of sunshine and the least rainfall throughout the year. UV index does reach 7 during these months, so take necessary sun precautions.The worst time to visit Wailuku
However, if looking to avoid heavy rainfall, it's advisable to steer clear of March and December as these months register the highest rainfall and number of rainfall days. Even then, the amount of rainfall is less than an inch so it's hardly torrential, and temperatures remain between 70.7°F (21.5°C) to 77.7°F (25.4°C).Spring weather in Wailuku
Spring in Wailuku runs from March to May. March sees the highest amount of rainfall for these months at 0.87" (22mm), though it tapers off dramatically to 0.43" (11mm) by May. The UV index begins to increase from 6 to 7 in this period. Daylight hours steadily increase from 12 hours in March to 13.3 hours in May.Summer weather in Wailuku
The summer months, from June to August, provide the most sunshine, peaking at 11.5 hours in June and July. It also consistently records the least rainfall, 0.2" (5mm) in June increasing slightly to 0.39" (10mm) in August. Wailuku's high tropical temperatures see little variation, and during summer months it remains between 77°F (25°C) to 79.5°F (26.4°C).Autumn weather in Wailuku
Autumn in Wailuku, running from September to November, sees a decline in sunshine from 9.6 hours in September to 7.2 hours in November. Rainfall starts to increase in this period from 0.39" (10mm) in September to 0.51" (13mm) in November. However, the number of rainfall days is still relatively low, making it a comfortable time to engage in outdoor activities.Winter weather in Wailuku
Winter in Wailuku is from December to February. This phase acknowledges the highest rainfall 0.87" (22mm) in December, which then lessens to 0.55" (14mm) by February. Daylight hours are at their lowest for the year, roundabout 11 hours, while UV index remains constant at 6. Even in these cooler months, temperatures range from 70.7°F (21.5°C) to 73.9°F (23.3°C), making this a mild winter experience.Weather in January
January in Wailuku, Hawaii, brings mild temperatures and slightly increased rainfall. High temperatures hover around 74.7°F (23.7°C), while low temperatures dip to approximately 71.6°F (22°C). Traditionally, the beginning of the year carries with it slightly increased rainfall, reaching 0.55" (14mm) over an average of 8.8 days. Weather in January »Weather in February
February brings a slight decrease in temperature, but the weather pattern remains largely consistent with January. Noteworthy is the increased rainfall, registering 0.75" (19mm) over an average of 8.5 days. Despite this increase, Wailuku remains pleasant due to consistent daylight hours and humidity levels. Weather in February »Weather in March
During March, Wailuku experiences an incrementally warmer climate with a consistent rainfall pattern. Although the temperature slightly increases, the highest rainfall for the year happens this month--that's 0.87" (22mm) after falling over an average of 11.9 days. Weather in March »Weather in April
April in Wailuku brings a reduction in rainfall, contributing to a warm and relatively dry month. The average rainfall notably decreases, measuring just 0.63" (16mm) over roughly 8.1 days, providing an opportunity to enjoy outdoor activities. Weather in April »Weather in May
May experiences a mild rise in temperature and reduction in rainfall, making it an appealing month for outdoor pursuits. The trend of falling rainfall continues, registering at 0.43" (11mm) spread over an average of 8.3 days. Increased sunshine hours and pleasant weather conditions make this month great for outdoor activities. Weather in May »Weather in June
June is characterized by consistently warm temperatures and minimal rainfall, making it an ideal month for tourists. In this month, the rainfall reaches its lowest yearly level at just 0.2" (5mm) over the course of roughly 6.6 days. Weather in June »Weather in July
July brings about the year's warmest temperatures and a slight increase in rainfall compared to the previous month. Although rainfall increases marginally to 0.39" (10mm) across roughly 8.5 days, it hardly has an impact on the overall weather. Weather in July »Weather in August
August is marked by warm temperatures consistent with July, while rainfall shows only a slight increase. The rainfall recorded measures around 0.43" (11mm) over approximately 8.7 days. This month provides ample sunshine hours and a comfortable level of humidity. Weather in August »Weather in September
In September, Wailuku experiences similar weather to August, with a small decrease in temperatures and steady rainfall. The month's noteworthy pattern is the slight decrease in rainfall to 0.39" (10mm) over an average of 8.1 days. Weather in September »Weather in October
October in Wailuku brings another month of consistent temperatures and a slight rise in the rainfall gauge. This month sees an increase in the rainfall by about 0.55" (14mm), dispersed across an average of 9 days. Though the weather remains predominantly dry, October marks the official arrival of the wet season. Weather in October »Weather in November
November brings a smaller drop in warm temperatures and slightly increased rainfall in comparison with October. Rainfall remains relatively consistent with a recorded increase at 0.51" (13mm) over about 7.7 days. As Wailuku transitions to cooler months, it provides a pleasant atmosphere for visitors seeking outdoor activities amid the natural surroundings. Wailuku's shift into November is marked by a subtle change to a still warm 77.7°F (25.4°C) from October's 79.3°F (26.3°C) in temperature. Weather in November »Weather in December
In December, Wailuku transitions into cooler, wetter weather, closing the year with increased rainfall and consistently mild temperatures. A higher average rainfall of 0.87" (22mm) decorates the landscape over an average of 9.2 days. Weather in December »Updated: Jul 16, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
The months with the lowest humidity in Wailuku are January and February, with an average relative humidity of 74%.
Throughout the year, there are 103.4 rainfall days, and 6.57" (167mm) of precipitation is accumulated.
January through June, November and December, with an average maximum UV index of 6, are months with the lowest UV index.
The coldest temperatures in Wailuku occur during February, when averages reach a peak of 73.9°F (23.3°C) and a low of 70.7°F (21.5°C).
The wettest months are March and December, with an average 0.87" (22mm) of rainfall.
June is the month with the least rainfall. Rain falls for 6.6 days and accumulates 0.2" (5mm) of precipitation.
With an average of 13h and 24min of daylight, June has the longest days of the year.
With an average of 11.5h of sunshine, June has the most sunshine of the year.
July and August, with an average relative humidity of 76%, are most humid months.
The months with the highest UV index are July through October, with an average maximum UV index of 7.
Wailuku's warmest month, September, generally records average temperatures ranging from a high of 79.9°F (26.6°C) to a low of 76.1°F (24.5°C).
The month with the shortest days is December, with an average of 10h and 54min of daylight.
Wailuku does not utilize Daylight Saving Time (DST). HST timezone is used over the entire year.
With an average of 7h of sunshine, December has the least sunshine of the year.
Average temperature
Wailuku, HI
The warmest month (with the highest average high temperature) is September (79.9°F).
The month with the lowest average high temperature is February (73.9°F).
The month with the highest average low temperature is October (76.5°F).
The coldest months (with the lowest average low temperature) are February and March (70.7°F).
Average pressure
Wailuku, HI
- Average pressure in January:
30"Hg - Average pressure in February:
30.01"Hg - Average pressure in March:
30.04"Hg - Average pressure in April:
30.05"Hg - Average pressure in May:
30.04"Hg - Average pressure in June:
30.03"Hg
- Average pressure in July:
30"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
29.97"Hg - Average pressure in October:
29.97"Hg - Average pressure in November:
30"Hg - Average pressure in December:
29.99"Hg
The month with the highest atmospheric pressure is April (30.05"Hg).
The months with the lowest atmospheric pressure are September and October (29.97"Hg).
Average wind speed
Wailuku, HI
- Average wind speed in January:
10.4mph - Average wind speed in February:
11.4mph - Average wind speed in March:
12.4mph - Average wind speed in April:
12.6mph - Average wind speed in May:
11.7mph - Average wind speed in June:
13.6mph
- Average wind speed in July:
13.5mph - Average wind speed in August:
13.4mph - Average wind speed in September:
11.9mph - Average wind speed in October:
11.4mph - Average wind speed in November:
12.9mph - Average wind speed in December:
11.7mph
The windiest month (with the highest average wind speed) is June (13.6mph).
The calmest month (with the lowest average wind speed) is January (10.4mph).
Average humidity
Wailuku, HI
The months with the highest relative humidity are July and August (76%).
The months with the lowest relative humidity are January and February (74%).
Average rainfall
Wailuku, HI
- Average rainfall in January:
0.55" - Average rainfall in February:
0.75" - Average rainfall in March:
0.87" - Average rainfall in April:
0.63" - Average rainfall in May:
0.43" - Average rainfall in June:
0.2"
- Average rainfall in July:
0.39" - Average rainfall in August:
0.43" - Average rainfall in September:
0.39" - Average rainfall in October:
0.55" - Average rainfall in November:
0.51" - Average rainfall in December:
0.87"
The wettest months (with the highest rainfall) are March and December (0.87").
The driest month (with the least rainfall) is June (0.2").
Average rainfall days
Wailuku, HI
- Average rainfall days in January:
8.8 days - Average rainfall days in February:
8.5 days - Average rainfall days in March:
11.9 days - Average rainfall days in April:
8.1 days - Average rainfall days in May:
8.3 days - Average rainfall days in June:
6.6 days
- Average rainfall days in July:
8.5 days - Average rainfall days in August:
8.7 days - Average rainfall days in September:
8.1 days - Average rainfall days in October:
9 days - Average rainfall days in November:
7.7 days - Average rainfall days in December:
9.2 days
The month with the highest number of rainy days is March (11.9 days).
The month with the least rainy days is June (6.6 days).
Average daylight / Average sunshine
Wailuku, HI
- Average daylight in January:
11h and 0min - Average daylight in February:
11h and 30min - Average daylight in March:
12h and 0min - Average daylight in April:
12h and 36min - Average daylight in May:
13h and 6min - Average daylight in June:
13h and 24min
- Average daylight in July:
13h and 18min - Average daylight in August:
12h and 48min - Average daylight in September:
12h and 18min - Average daylight in October:
11h and 42min - Average daylight in November:
11h and 6min - Average daylight in December:
10h and 54min
The month with the longest days is June (Average daylight: 13h and 24min).
The month with the shortest days is December (Average daylight: 10h and 54min).
- Average sunshine in January:
8h and 36min - Average sunshine in February:
8h and 54min - Average sunshine in March:
8h and 42min - Average sunshine in April:
9h and 12min - Average sunshine in May:
11h and 0min - Average sunshine in June:
11h and 30min
- Average sunshine in July:
11h and 12min - Average sunshine in August:
9h and 12min - Average sunshine in September:
9h and 36min - Average sunshine in October:
8h and 12min - Average sunshine in November:
7h and 12min - Average sunshine in December:
7h and 0min
The month with the most sunshine is June (Average sunshine: 11h and 30min).
The month with the least sunshine is December (Average sunshine: 7h and 0min).
Average sunshine days
Wailuku, HI
- Average sunshine days in January:
19.3 days - Average sunshine days in February:
16.6 days - Average sunshine days in March:
15.2 days - Average sunshine days in April:
17.5 days - Average sunshine days in May:
18.5 days - Average sunshine days in June:
19.9 days
- Average sunshine days in July:
16 days - Average sunshine days in August:
15.8 days - Average sunshine days in September:
17.3 days - Average sunshine days in October:
17.1 days - Average sunshine days in November:
17.4 days - Average sunshine days in December:
17.7 days
The month with the most sunshine days is June (19.9 days).
The month with the least sunshine days is March (15.2 days).
Average UV index
Wailuku, HI
The months with the highest UV index are July, August, September and October (UV index 7).
The months with the lowest UV index are January, February, March, April, May, June, November and December (UV index 6).
Average cloud cover
Wailuku, HI
The month with the most cloud cover is March (Cloud cover 30).
The months with the least cloud cover are June and September (Cloud cover 21).
Average visibility
Wailuku, HI
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
