Waimanalo (HI) Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Waimanalo, Hawaii, United States of America. These values are calculated using 30 years of data (1990–2020) to ensure accuracy. Let's explore the details to provide you with a complete overview.

Waimanalo has a relatively dry climate with low precipitation, averaging 458 mm (18 in) of rainfall annually. It experiences a distinct dry season during certain months. Refer to our detailed charts below to see the seasonal variation.

Monthly Precipitation Levels

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

Significant seasonal changes in precipitation occur throughout the year. During the wettest month, December receives substantial rainfall, averaging 58 mm (2.3 in) of precipitation, recorded across 11 rainy days.

In contrast, the driest month, July brings less rainfall, with 25 mm (1 in) over 8 rainy days.

December, the wettest month, has a maximum daytime temperature of 26°C (79°F). The city receives 199 hours of sunshine in this period. During the driest month July you can expect a temperature of 27°C (81°F). For more detailed insights into the city's temperatures, visit our Waimanalo Temperature page.

Waimanalo's average annual precipitation is 458 mm (18 in). Let's compare this to some popular worldwide tourist destinations:

Chicago, USA, sees an annual precipitation of 1062 mm (42 in), with rain and snow contributing to its humid climate.

Meanwhile, Buenos Aires, Argentina, enjoys a humid subtropical climate with 1000 mm (39 in) of annual rainfall, mostly in the summer.

Adelaide, Australia, enjoys 511 mm (20 in) of annual precipitation, with dry summers and wet winters.

Kuala Lumpur, Malaysia, receives 2529 mm (100 in) of annual rainfall, characteristic of its equatorial tropical rainforest climate, with consistent rainfall throughout the year and peak months during March and November.

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.

Climate change is affecting precipitation patterns worldwide, including Waimanalo (HI):

• 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.

• The U.S. has a significant number of thunderstorms every year, with over 14.6 million taking place across the world annually.
• Approximately 70% of lightning bolts strike land rather than oceans.
• A storm named John was the longest-lasting Pacific tropical storm, continuing for 31 days. As it crossed the dateline twice, it changed status from a hurricane to a typhoon and back to a hurricane.

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