Wailuku (HI) Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Wailuku, Hawaii, United States of America. The figures are based on a 30-year period (1990–2020) to provide a reliable average. Now, let's break down all the details for a clearer picture.

With annual rainfall averaging 386 mm (15 in), Wailuku maintains relatively low precipitation levels throughout the seasons. However, it does have a distinct dry season during certain months, creating distinct patterns as demonstrated in our detailed graph below.

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm (0.01 in))

The climate in Wailuku shows significant variation throughout the year. Expect 55 mm (2.2 in) of precipitation during the wettest month March, distributed over 13 rainy days.

In contrast, June offers drier and sunnier days, with around 15 mm (0.6 in) of rainfall over 8 rainy days.

March, the wettest month, has a maximum daytime temperature of 27°C (81°F). The city receives 240 hours of sunshine in this period. During the driest month June you can expect a temperature of 29°C (84°F). For more detailed insights into the city's temperatures, visit our Wailuku Temperature page.

Wailuku's average annual precipitation is 386 mm (15 in). Let's compare this to some popular worldwide tourist destinations:

In Toronto, Canada, annual precipitation averages 964 mm (38 in), with snowy winters and rainy summers.

Osaka, Japan, experiences 1507 mm (59 in) of rainfall annually, spread across the year with wetter summers.

Melbourne, Australia, has 690 mm (27 in) of rainfall annually, spread fairly evenly throughout the year.

Mumbai, India, experiences a tropical monsoon climate with 1860 mm (73 in) of annual rainfall, with the majority of precipitation happening during the monsoon season from June to September.

Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.

Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.

Precipitation has a very strong role in determining the local climate and ecosystem:

• Changing Rainfall Patterns: Global warming causes drastic changes in the patterns of rainfall. Some areas have been experiencing increased frequency and intensity of rainfall, while other areas experience longer dry spells or even droughts.
• Local Impacts: Many regions are experiencing heavier rainfall in the winter months and drier, hotter summers. This affects agriculture, water resources, and ecosystems.

• "Ginger" was the longest-lasting Atlantic tropical storm, which spun around the open ocean for 28 days in 1971.
• The world's largest snowflake was recorded in the Guinness Book of Records, at 38 cm (15 inches) wide and 20 cm (7.9 inches) thick. The snowflake fell at Fort Keogh, Montana, USA, on 28 January 1887.
• The greatest snowfall recorded was on Mt. Rainier, Washington State, USA, over 31.5 meters (103 feet) fell during the winter of 1972.

For more detailed information about Wailuku (HI)'s weather, including sunshine hours, humidity levels, and temperature data, visit our Wailuku (HI) Climate page.