Wailuku (HI) Temperature by Month
The average annual maximum temperature in Wailuku, Hawaii, United States of America is 28°C (82°F), with little variation between seasons. This page covers monthly averages, day-night differences, and how Wailuku compares to cities worldwide.
Wailuku Monthly Temperatures
With minimal seasonal shifts, Wailuku experiences a constant climate year-round. Maximum daytime temperatures range from a very warm 30°C (86°F) in August to a comfortable 26°C (79°F) in February. At night, temperatures range from 24°C (75°F) in August to 20°C (68°F) in February.
The chart below illustrates the average maximum day and minimum night temperatures in Wailuku by month:
The coolest part of the day is typically between 4 AM and 6 AM, while 3 PM is usually the warmest, when solar heating is at its peak. August, the city's warmest month, averages 285 hours of sunshine.
The chart below shows the average temperature throughout the year:
Temperature: Wailuku vs the United States of America
The map below shows the annual temperature across the United States of America. You can also select individual months if you want to compare a specific time of year.
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Wailuku vs World: Temperature Compared
Wailuku's average annual maximum temperature is 28°C (82°F). To put that in context, here's how it compares to a few well-known destinations:
Lisbon, Portugal averages 21°C (70°F) annually — warm summers, mild winters, and rain mainly in the cooler months.
Reykjavík, Iceland averages 9°C (48°F) a year — mild summers by Icelandic standards, but cold winters and frequent wind.
San Francisco, USA averages 19°C (66°F) annually, but with little seasonal variation — summers are often cool and foggy, winters mild.
Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.
What Does the Temperature Feel Like in Wailuku?
Temperature alone doesn't tell the whole story — humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.
In Wailuku, February is the coolest month, with average highs of 26°C (79°F) and humidity around 75% — considered high. In August, the warmest month, temperatures average 30°C (86°F) with 69% humidity — conditions that feel high. For a full picture, see our humidity page.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
Whether a city sits on the coast or deep inland makes a significant difference to its climate. Coastal areas tend to have more stable temperatures year-round — large bodies of water absorb heat slowly in summer and release it gradually in winter, keeping extremes in check. Cities far from the sea don't benefit from that buffer, which is why continental climates tend to have hotter summers and colder winters than their coastal counterparts at the same latitude.
For more on Wailuku's weather — including monthly rainfall, sunshine hours, and humidity — visit our Wailuku climate page.
