Saipan weather in September

Saipan-forum threads on July weather describe it as hot, humid and sunny with a real chance of showers, part of the wet season though posters say the rain itself rarely lasts more than a few minutes at a stretch. Morning showers and the odd afternoon thunderstorm are typical rather than exceptional this time of year. The bigger factor to watch is typhoon risk: the window from July through October is when tropical systems most often affect the Northern Marianas, capable of bringing widespread heavy rain well beyond a normal shower. Regulars recommend checking the tropical outlook regardless of how the week's forecast looks otherwise, since a system can develop and strengthen with real speed this time of year. The record: 29.6C days feeling like a punishing 34C, 24.1C nights, a notably high 239mm across 22.8 days, 82 percent humidity, a 29.5C sea and 10.3 hours of sun.

February is one of the months regulars name for Saipan, and their reason is the wind rather than the sun. The trade winds run roughly September to March and hold the island in the mid-80s Fahrenheit; when they stop later in the spring the same island climbs into the high 80s and low 90s by the middle of the day. Our row's 35.7 kph average is that cooling, and it is the highest wind in this dataset's tropical rows. The rainy season - August to November, when it rains most days for an hour or two - is well behind. Our 12.4 precipitation days is a trace-day count rather than a wet month: 83.2mm spread across all of them. The record: 27.7C days over 22.8C nights, humidity 75 percent, 10.7 hours of sun and a 27.9C sea.

March is the last month of the trade winds on the Saipan forum's calendar - they run from about September to March and are what keeps the island in the mid-80s F; once they drop away from April onwards the afternoons climb into the high 80s and sometimes the low 90s. The rains people ask about belong to August through November, when it falls most days but usually for an hour or two at a time, so March sits well clear of that. On typhoons, regulars are matter-of-fact: they come through every so often, years can pass without one, and Guam usually takes the worst of anything that does. The record: 28.6C days feeling like 31C, 23.3C nights, 15.1 precipitation days, a 27.8C sea and a 30.5 kph trade wind.

Forum posters describe October as squarely inside Saipan's rainy season (roughly August-November), with rain most days but usually limited to an hour or two rather than an all-day event - though some stretches do bring a multi-day storm system while other weeks stay mostly sunny with just a brief shower. On typhoons: none have passed directly through in several recent years, though they do come around occasionally, and posters note Saipan typically doesn't take the worst of a storm's force the way Guam further south sometimes does.