Although the climate is hot and humid year-round, it's hotter and rainier from November to April (the hurricane season).
The frequency of hurricanes has increased dramatically in recent years. The old rule of thumb was one every 7-10 years, but during the five-year period up to 1991, three major storms hit Tutuila.
Many believe this is related to rising ocean temperatures caused by climate change—and things could get worse in the future. Most hurricanes move into the area from the north but they can also come from the east or west.
Temperatures are usually steady, but the stronger winds from May to October ventilate the islands. The prevailing tradewinds are from the east or southeast, with west or northwest winds and long periods of calm during the wetter season.
As warm easterlies are forced up and over Tutuila's Rainmaker Mountain, clouds form that drop their moisture on the harbor just to the west. Apia receives only half the annual rainfall of Pago Pago. From December to March the rain can continue for days, while the rest of the year it often comes in heavy downpours. The exact amount of rain in any given month varies greatly from year to year, and much of it falls at night. Actually, the weather can change from bright sunshine to heavy rain within 5 or 10 minutes at any time of year.
You can hear a recorded weather report with tide times by calling 699-9333.