Pohnpei-Between Time & Tide . Weather & Climatology

Pohnpei's Climate

n one of the many travel books written about Micronesia in the 60's and 70's, the chapter reserved for Pohnpei has a one-word title: 'Rain'. Rain is, indeed, a substantial part of the Pohnpei experience. The island's imposing mountains serve as a wall, catching much of the moisture in passing clouds. Yet, the mountains aren't quite high enough to act as a complete block. Consequently, the amount of rainfall on the windward and leeward sides of the island does not differ greatly. Rain patterns are more-or-less uniform. The coasts get the least rain and the amount increases steadily as one moves towards the zenith at the island's nearly impenetrable center. It is said that Pohnpei is the second rainiest place on earth, after Mt. Waiale'ale on

the island of Kaua'i. Kolonia gets between 170 and 200 inches of rainfall annually, while the island's interior nets over 400 inches! Pohnpei's close proximity to the equator, right in the middle of the intertropical convergence zone (ITCZ), eliminates any major seasonal change. Converging trade winds from the northwest and southeast are heated and sent upwards, carrying large amounts of moisture and bringing heavy precipitation.

Years of meteorological data have yielded this sobering statistic; there are an average of only three entirely cloudless days each year on Pohnpei. Fortunately for outdoor enthusiasts, rain tends to be of the most convenient type; it's warm and falls very heavily, but only sporadically. The average day might consist of an hour-long drenching here and a couple of fifteen minute deluges there, separated by periods of warm sun, gorgeously fluffy cumulous clouds and the bluest sky most folks have seen. The largest part of the rainfall comes at night, when on-shore breezes are quickly cooled as they rise up the mountain slopes. Put simply, you have to be ready for rain at all times and consider it when making any plans. Tarps are your best friend on any camping or hiking trip. Trying to sleep, while soaked to the skin, is one of the most miserable experiences you'll find outdoors. Locals don't seem to pay much attention to the rain. Umbrellas are rare; most people are content to make a dash to the nearest tree and wait out a sudden cloud-burst before going on their way.

Major wind storms and destructive typhoons are uncommon on Pohnpei. Typhoons can't form at the equator where coriolis effect is zero. Rather, they brew north of Pohnpei and sweep west where they cause the greatest damage in places like Yap, Guam and the Northern Marianas. The last great typhoon to hit the island was in 1907. It destroyed practically all the tree crops on the island, leveled the town of Kolonia and caused great stone walls to tumble at Nan Madol.

TEMPERATURE & SEASONAL CHANGE

According to a local story-teller, a traveler once asked an elderly Pohnpeian man when the dry season was. The old man smiled, and with a twinkle in his eye, he said, "I think it was last Tuesday." Seasons on Pohnpei can be thought of most accurately in this way: the Season of Rain and the Season of More Rain. The driest months seem to be January and February, while May and June are the wettest. Winds are stronger during the winter and temperatures are slightly lower than in early summer. However, the average daily air temperature of 80° is quite constant; so constant, that after one has acclimated for awhile, a temperature drop of a few degrees warrants the donning of a sweatshirt. And after a year or two on the island, you become acutely aware of every minute change. On beautiful 77° evenings, you find yourself saying absurd things like, "Gosh, it's freezing!"

KEEPING THE RAIN OUT

We found that five-gallon paint buckets are great for taking things anywhere where you'll be in a boat or without good cover. They seal tightly, and keep out the rain, the sea spray and any pesky animals that might like to root through your stuff.

In 1997, Typhoon Isa passed Pohnpei on its way to Guam. Winds were mild, but more than twelve inches of rain fell in twelve hours! Major landslides, mostly in the municipalities of Sokehs and Kitti claimed the lives of more than twenty people and destroyed houses and farms.

Text by Alex Zuccarelli 2003.
Image/Photo credits: Articles from Pacific Daily News - April 22-23, 1997 (format modified to minimize file size). All other photos, images and maps property of Alex Zuccarelli.
All photographs on this page were used with the written permission of their perspective owners, except where otherwise indicated.

Primary Sources

Ashby, Gene
1993. Pohnpei: Island Argosy. Rainy Day Press: Eugene.
Bernart, Luelen, John L. Fischer, Saul H. Riesenberg and Marjorie G. Whiting, translators and editors
1977. The Book of Luelen. National University Press: Canberra.
Castro, Peter & Michael E. Huber
2000. Marine Biology, 3rd Edition. McGraw Hill.
Duxbury, Alyn C., Alison B. Duxbury & Keith A. Sverdrop.
2000. An Introduction to the World's Oceans, 6th Ed. McGraw-Hill Companies, Inc.
Kruk, Remke, editor
1981. The Tropical Rain Forest: A First Encounter. Springer-Verlag: Heidelberg.
Levy, Neil M.
1996. Micronesia Handbook. Moon Publications, Inc.: Chico.
Merlin, M., D. Jano, W. Raynor, T. Keene, J. Juvik & B. Sebastian
1992. Tuhke en Pohnpei (Plants of Pohnpei). Department of Education, Pohnpei State, Office of Historic Preservation, FSM & Environment and Policy Institute, East-West Center, University of Hawaii.
Ward, Martha C.
1989. Nest in the Wind: Adventures in Anthropology on a Tropical Island. Waveland Press, Inc., Prospect Heights.

On-Line Resources