Climate and monthly weather forecastSaipan, Northern Mariana Islands, USA
Climate and monthly weather forecast
The climate of Saipan
Saipan, part of the Northern Mariana Islands in the USA, experiences a tropical rainforest climate, denoted as 'Af' by the Köppen climate classification. It is located in the western Pacific Ocean and has a typically humid, tropical climate throughout the year. On average, temperatures range from 73.4°F (23°C) to 85°F (29.4°C), making Saipan a consistently warm destination. However, there is a noticeable fluctuation in the number of rainfall days, from 17 to 23 days, showcasing a high degree of variability.One constant of Saipan's climate is the sea temperature, which remains consistently warm from 81°F (27.2°C) to 84°F (28.9°C). This offers ideal conditions for water-based activities throughout the year. The steady temperatures both, on land and sea, are a testament to Saipan's tropical location. Levels of sunlight, while abundant, vary from 5 hours to 7 hours daily, reflecting the tropical nature of the island.
The rainfall patterns are rather fascinating. Rainfall varies dramatically, with the lowest average rainfall of 2.4" (61mm) one month and soaring to a high 12.4" (315mm), highlighting the unpredictable rain pattern typical of tropical climates. Extreme weather conditions can be expected when the average monthly rainfall exceeds 10" (254mm).
The best time to visit Saipan
Despite the tropical rainforest climate, the ideal period of time to visit Saipan is between the months of February and April. During this time, the island sees moderate rainfall quantities measuring between 2.4" (61mm) to 5" (127mm). This reflects a period comparatively drier than the rest of the year. Temperatures are relatively moderate as well, staying around 79.7°F (26.5°C) to 83.1°F (28.4°C). Daylight hours are ample as well, increasing from 11.7 hours to 12.5 hours, which allows tourists ample time for outdoor activities.The worst time to visit Saipan
The months from July to October can be considered the least favorable time to visit Saipan. This period records the heaviest rainfall, ranging from 10.2" (259mm) to 12.4" (315mm). Consequently, the frequency of rainfall days is also at its peak, from 19 to 22 days a month. Notwithstanding, temperatures during these months maintain a consistent warmth of around 84°F (28.9°C). These conditions can be problematic for outdoor activities, hence it is advisable to plan accordingly.Spring weather in Saipan
In Saipan, the spring season from March through May, offers an ideal tropical getaway for visitors. March experiences an average high temperature of 79.8°F (26.6°C) and a relatively low volume of rainfall at 2.4" (61mm). However, May brings slightly higher rainfall at 3.8" (97mm) but also extends daylight to a generous 12.8 hours, ensuring extended hours for outdoor exploration.Summer weather in Saipan
Summer in Saipan, from June to August, although hot, witnesses the highest rainfall with values up to 12.4" (315mm). Temperatures remain steady, with a high of 85°F (29.4°C) in June and a consistent sea temperature of 84°F (28.9°C) contributing to the humid environment. Regardless of the high rainfall, summer in Saipan still offers between 5 to 6 hours of sunshine daily, balancing the climate.Autumn weather in Saipan
The autumn months from September to November, in Saipan, carry on with high rainfall and steady temperatures. Compared to other times of the year, September sees more daylight at 12.2 hours while November records the least daylight, averaging 11.4 hours. Despite the decrease in daylight and persistent rainfall, temperatures remain relatively constant at an average of 83.3°F (28.5°C) in November.Winter weather in Saipan
The winter season in Saipan, from December through February, is surprisingly mild with temperatures resting between 73.4°F (23°C) and 79.7°F (26.5°C). While December and January experience high volumes of rainfall, 5.9" (150mm) and 3.8" (97mm) respectively, February is relatively dry with a mere 2.4" (61mm). This highlights the unpredictability of Saipan's rainfall pattern even within the traditional dry season.Weather in January
The weather in Saipan, in the Northern Mariana Islands, begins the year calmly. Saipan experiences a high temperature of 81.2°F (27.3°C) and a low value of around 73.4°F (23°C), a slight difference from the previous month. The city itself benefits from the sea's warmth, with a temperature of 82°F (27.8°C). Weather in January »Weather in February
In Saipan, February reveals the consistency of the tropical climate. Compared to January, rainfall increases to 4.4" (112mm), and temperatures range between a lower boundary of 72.9°F (22.7°C) and a peak value of 79.7°F (26.5°C). Weather in February »Weather in March
Transiting into March, weather patterns in Saipan shift slightly. Settling at 2.4" (61mm), rainfall reduces compared to February, offering drier conditions. The lowest and highest temperatures moderately hover around 73.1°F (22.8°C) and 79.8°F (26.6°C) respectively. Weather in March »Weather in April
As Saipan enters April, it brings with it a rise in rainfall, peaking at 5" (127mm) for the month. In terms of temperatures, deviations are noted between a minimum recorded temperature of 73.9°F (23.3°C) and a top of 83.1°F (28.4°C). Weather in April »Weather in May
May sees Saipan’s weather conditions continue to provide comfortable temperatures. The gap between the coldest recorded value, 75.5°F (24.2°C), and the highest, 84.4°F (29.1°C), creates a pleasantly warm environment. Despite the rainfall increase, residents still enjoy long sunny hours, which maximizes daylight efficiency. Weather in May »Weather in June
The month of June showcases the dependable nature of Saipan's climate. With rainfall totaling 5" (127mm), June reveals a discussed steady trend. Amid temperatures that fluctuate from 75.3°F (24.1°C) to 85°F (29.4°C), the city experiences its longest daylight hours. Weather in June »Weather in July
July marks the onset of Saipan’s rainy season with a notable leap to 10.2" (259mm) of rainfall. The temperature extremes in July remain suitably warm, varying between a cozy 75.1°F (23.9°C) and a warm 84.1°F (28.9°C). Rich, tropical greenery reaches its most vibrant hue due to the steady and nutrient-rich rain. Weather in July »Weather in August
In Saipan, August stands as the rainiest month, with a hefty rainfall of 12.4" (315mm). Temperature swings are seen from a low of 75.2°F (24°C) to an upper limit of 84°F (28.9°C). The ocean temperature stabilizes at 84°F (28.9°C), providing some much-needed relief from the humidity. Weather in August »Weather in September
September features substantial yet decreasing rainfall in Saipan with the precipitation level at 11.7" (297mm). Comparing temperatures, lows dip slightly to 75°F (23.9°C), while the maximum soars to a stable 83.7°F (28.7°C). Weather in September »Weather in October
October offers a palpable breather from the heavy rainfall, recording 11" (279mm) that decrease slightly from the previous month. Holding a minimum temperature of 74.9°F (23.8°C) and a maximum of 83.3°F (28.5°C), October's weather retains ample warmth. Weather in October »Weather in November
November, the last month of the autumn in Saipan, is warm month, with temperature in the range of an average high of 83.3°F (28.5°C) and an average low of 75°F (23.9°C). Saipan's November reports an average high-temperature of a still warm 83.3°F (28.5°C), exhibiting a minor difference from October. Weather in November »Weather in December
In December, Saipan's weather takes on a more tranquil demeanor as the year ends. Rainfall estimates at about 5.9" (150mm), setting a significantly lower level than in previous months. The city registers temperatures varying from a low of 74.1°F (23.4°C) to a high of 81.4°F (27.4°C), presenting fairly pleasant conditions. Weather in December »Updated: Aug 18, 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
In Saipan, during the entire year, the rain falls for 244 days and collects up to 83.39" (2118mm) of precipitation.
February is Saipan's coldest month, registering average high temperatures of 79.7°F (26.5°C) and lows of 72.9°F (22.7°C).
February and March, with an average ocean temperature of 80.6°F (27°C), are months with the coldest seawater.
February through September, with an average maximum UV index of 12, are months with the highest UV index.
The month with the least rainfall is March, when the rain falls for 20 days and typically collects 2.4" (61mm) of precipitation.
March through June, with an average of 7h of sunshine, are months with the most sunshine.
June, with its high-temperature average of 84.9°F (29.4°C) and a low-temperature average of 75.4°F (24.1°C), is the warmest month.
The months with the warmest seawater are June through November, with an average ocean temperature of 84.2°F (29°C).
The month with the longest days is June, with an average of 13h and 0min of daylight.
August is the month with the most rainfall. Rain falls for 21 days and accumulates 12.44" (316mm) of precipitation.
The months with the least sunshine are August through December, with an average of 5h of sunshine.
The months with the lowest UV index in Saipan are November and December, with an average maximum UV index of 9.
With an average of 11h and 12min of daylight, December has the shortest days of the year.
Saipan does not utilize Daylight Saving Time (DST). ChST timezone is used over the entire year.
Average temperature
Saipan, Northern Mariana Islands, USA
The warmest month (with the highest average high temperature) is June (85°F).
The month with the lowest average high temperature is February (79.7°F).
The month with the highest average low temperature is May (75.5°F).
The coldest month (with the lowest average low temperature) is February (72.9°F).
Average rainfall
Saipan, Northern Mariana Islands, USA
The wettest month (with the highest rainfall) is August (12.4").
The driest month (with the least rainfall) is March (2.4").
Average rainfall days
Saipan, Northern Mariana Islands, USA
- Average rainfall days in January:
23 days - Average rainfall days in February:
19 days - Average rainfall days in March:
20 days - Average rainfall days in April:
19 days - Average rainfall days in May:
20 days - Average rainfall days in June:
17 days
- Average rainfall days in July:
19 days - Average rainfall days in August:
21 days - Average rainfall days in September:
19 days - Average rainfall days in October:
22 days - Average rainfall days in November:
22 days - Average rainfall days in December:
23 days
The months with the highest number of rainy days are January and December (23 days).
The month with the least rainy days is June (17 days).
Average sea temperature
Saipan, Northern Mariana Islands, USA
The best months for swimming (with the highest average sea temperature) are June, July, August, September, October and November (84°F).
The coldest months (with the lowest average sea temperature) are February and March (81°F).
Average daylight / Average sunshine
Saipan, Northern Mariana Islands, USA
- Average daylight in January:
11h and 18min - Average daylight in February:
11h and 36min - Average daylight in March:
12h and 6min - Average daylight in April:
12h and 30min - Average daylight in May:
12h and 48min - Average daylight in June:
13h and 0min
- Average daylight in July:
12h and 54min - Average daylight in August:
12h and 36min - Average daylight in September:
12h and 12min - Average daylight in October:
11h and 48min - Average daylight in November:
11h and 24min - Average daylight in December:
11h and 12min
The month with the longest days is June (Average daylight: 13h and 0min).
The month with the shortest days is December (Average daylight: 11h and 12min).
The months with the most sunshine are March, April, May and June (Average sunshine: 7h).
The months with the least sunshine are August, September, October, November and December (Average sunshine: 5h).
Average UV index
Saipan, Northern Mariana Islands, USA
The months with the highest UV index are February, March, April, May, June, July, August and September (UV index 12).
The months with the lowest UV index are November and December (UV index 9).
