My Summary of Hawaii Weather and Climate
I receive
more email requests for Hawaii climate information than any
other topic!
Here are my answers. ( For current weather, click
here ).
Temperatures in Hawaii are very stable because it is surrounded
by a vast, warm ocean.
All the air over the islands must first pass over thousands
of miles of that ocean before it
reaches the islands. If the air comes from a cooler place, it
warms up. It it comes from
a warmer place, it cools off. The ocean water temperature off
Hawaii only varies from
about 76 to 81 degrees F.
Typical
sea water temperatures for Honolulu,
Hawaii ( Island of Oahu ) |
| Jan 76 °F |
Feb 76 °F |
Mar 76 °F |
Apr 76 °F |
May 78 °F |
Jun 79 ° F |
| Jul 80 °F |
Aug 80 °F |
Sep 81 °F |
Oct 81 °F |
Nov
79 °F |
Dec 77 ° F |
|
Air Temperature in Hawaii
Hawaii
air temperatures follow a seasonal pattern. At sea level, the
all day average
air temperature varies from about 78 degrees in August to 72
degrees in February.
Temperature varies depending on location.
There are two main factors: Altitude and exposure of the area
to prevailing winds.
The prevailing winds are from the northeast. The northeast side
of each island
is called the windward side. The windward side of each island
tends to be cooler and wetter.
The high temperatures here rarely reach 90° F.
The leeward side is warmer and drier, Temperatures exceed 90°
F several days a year.
The temperatures at altitudes below 1000 feet very rarely
drop to 50° F .
Above 8000 feet, there is occasional freezing and even snow.
Precipitation
Snow is rare in Hawaii, but
does occur at very high elevations, above 8000 feet.
Rain:
Offshore, the rainfall is about 25 inches a year. As the warm,
moist air passes
over the islands, it must rise and cool as it passes over the
hills and mountains. As it cools,
water condenses. Therefore, the amount of rain depends strongly
on location.
Hawaii's winds usually come from the Northeast. As those trade
winds rise they drop water
on the land beneath them. Therefore, the windward side of the
islands have much more rain
than the leeward sides. In general, the closer you are to the
mountains on the windward side
( usually the northeast ), the wetter it is.
The air, having lost much of its water on the windward side,
and warming again as it moves
down the leeward side of the mountains, clears up. It's clouds
dissipate and the rainfall
diminishes. The driest and sunniest places in Hawaii are close
to the ocean on the leeward,
( usually southwest ) side of any island.
The rainiest
season of the year, in most places, is winter. The seasonal
difference is greatest
at moderate elevations, and small at elevations above 2000 feet.
Rain may
be very heavy at times. Floods are not uncommon near rivers
on the windward
side of islands.
Winds
The trade winds that flow over and around the
Hawaiian islands most of the time, must pass
over mountains and through valleys. These winds are usually
above 12 mile per hour.
As they encounter these obstacles, wind speeds are increased
as they pass through valleys
and their direction changes as eddies form. Winds may be gusty,
strong and unpredictable
as a result. Winds above 60 miles per hour are rare Hawaii weather
events, occurring only about
every five years.
Hurricanes in Hawaii
Hurricanes rarely hit Hawaii. Damaging hurricanes that do
significant damage
have been separated by about 10 years on the average. Hawaiian
hurricanes are usually
generated between Hawaii and Baja California.
The most recent severe hurricane, Iniki, struck Kauai and parts
of Oahu in 1991.
For wonderful
climate maps and charts of many other phenomena in Hawaii
you will absolutely love Atlas
of Hawaii
|
Hawaii climate and weather as locals know
it