Saipan Monthly Rainfall & Precipitation
This page shows both the average monthly rainfall and the number of rainy days in Saipan, Northern Mariana Islands. Long-term data from 1990 to 2020 was used to calculate these averages. Let's now guide you through the details for a complete overview.
Saipan is known for its substantial rainfall, with annual precipitation reaching 1897 mm (75 in). While the overall climate is wet, there are notable seasonal patterns that create interesting contrasts, as demonstrated in our graph below.
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, August receives substantial rainfall, averaging 352 mm (14 in) of precipitation, recorded across 21 rainy days.
In contrast, the driest month, March brings less rainfall, with 50 mm (2 in) over 20 rainy days.
August, the wettest month, has a maximum daytime temperature of 30°C (86°F). During the driest month March you can expect a temperature of 28°C (82°F). For more detailed insights into the city's temperatures, visit our Saipan Temperature page.
Explore Saipan's Historical Precipitation: 1976-2026
Browse day-by-day precipitation records for Saipan spanning 51 years. Select any month and year to see actual rainfall and snowfall recorded on each day.
Annual Rainfall in Northern Mariana Islands: City Comparison
The map below shows the annual precipitation across Northern Mariana Islands. You can also select the different months in case you are interested in a specific month.
heavy rainfall
high
moderate
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Saipan vs World: Rainfall Compared
Saipan's average annual precipitation is 1897 mm (75 in). Let's compare this to some popular worldwide tourist destinations:
New York City, USA, receives 1276 mm (50 in) of rainfall annually, with precipitation evenly distributed throughout the year.
In Shanghai, China, the annual average precipitation is 1347 mm (53 in), with a humid subtropical climate.
Perth, Australia, receives 565 mm (22 in) of rainfall annually, mostly during the winter months.
Bangkok, Thailand, experiences a tropical monsoon climate with 1668 mm (66 in) of annual rainfall, with the heaviest precipitation occurring during September and October.
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 Saipan's weather, including sunshine hours, humidity levels, and temperature data, visit our Saipan Climate page.
