Rain, Sun & Wind - When and where!

Recording of detailed climate data on Pohnpei began in the German colonial period and intensified with the Japanese and American administrations. The following information was taken from a 2004 technical report produced by WERI (Water and Environmental Research Institute of the Western Pacific - University of Guam).

CLOUD ZONE

Pohnpei lies within the Intertropical Convergence Zone (ITZ)--a swath of the equatorial Pacific that is one of the wettest, cloudiest areas on earth.

HOW MUCH RAIN AND WHERE?

Pohnpei's interior mountains have a great influence on how much rain falls and where. The average rainfall around the coasts is roughly half as much as that of the central highlands.


The driest area is around Pohnpei's International Airport in the northern lagoon about one mile north of Kolonia, where the annual rainfall average is 140 inches. The wettest spot on the island is at its mountainous center, where the annual rainfall average is 325 inches.

The western side of Pohnpei is slightly wetter than the eastern side. This may be because the mountains are closer to the coast on the western side.

SEASONS - WET AND WETTER

Pohnpei doesn't have much of a dry season comparatively to most other places around the world.

January and February are the driest months of the year with the February average at about 10 inches (roughly what most of Southern California gets in an entire year). The driest month on record was January 1998 with 0.64 inches.

April and May are the wettest months. May's average is about 20 inches--almost 2 feet! The highest monthly rainfall on record was in August of 1992 when a whopping 38 inches fell on the island. The driest years in Pohnpei's history have always followed El Nino.

From June through December, you can expect an average of about 16-17 inches of rain per month.

WHAT TIME OF DAY IS THE WETTEST?

Pohnpei has a tendency to get its heaviest showers around noon, diminishing toward late afternoon. This pattern is the most pronounced during the summer.

As a general rule, mornings and late afternoon are more likely to be dry and sunny than mid-day and early afternoon (noon - 2:00 pm). By evening, the afternoon rains have usually subsided and there's a dry period. Heavy rain at night is common.

SUNLIGHT

Your plants will have the greatest chance for sunlight from 8 AM to noon and then from about 2:30 to 5:00 PM.

Being near the equator, Pohnpei's sun is very intense, and the morning light will be better for most plants than the harsher late afternoon light. But, for sun-loving plants like basil, tomatoes, and rosemary, you'll want to get your plants out under the naked sun for as long as possible.

Container gardening allows you to move things around to follow the sun. Where I live, the morning sun is full on the east balcony until noon and full on the south balcony from 1 PM on. I move all my pots from one side of the house to the other to get the most out of the light. It's a bit of a task, but I think it pays off.

WIND

Pohnpei is strongly affected by a system of trade winds which blow from the east and are heaviest from January through April.

If you keep your plants on a sheltered porch or under a plastic roof, be aware that rain often blows from the east. For this reason, I keep my pots on the south side of the house whenever I'm not home. If blowing rain starts up, they stay dry, whereas they would be drowned on the east side of the house.