Hawaii Climate

[sacha777]

I have always wondered why Hawaii dry season in summer, and wet season in winter.

In a typical tropical climate, dry season is in winter and wet season in summer (e.g. in the Caribbeans, Florida, Mexico, Mauritius, Nothern Australia).

Hawaii seems to be an exception.

Why?

[reef]

Welcome to the forum

Its mostly to do with the trade winds and positioning of high pressure cells.

http://www.wrcc.dri.edu/narratives/HAWAII.htm

Essentially during the summer as the high pressure belt over the tropics moves northwards the predominent direction of the trade winds changes to a more northerly direction and the weather is much drier. During Autumn onwards as the pressure belt moves back southwards the wind changes direction and creates more orthographic rainfall (air hitting the mountains and dropping rain as it rises) as well as the effect of stray tropical storms and hurricanes.

[sacha777]

Thanks Reef.

I found this on Wikipedia, I don't know if it's right though: "Honolulu experiences a tropical savanna climate (Köppen classification As) with a mostly dry summer season due to a rainshadow effect that suppresses summer rains"

What do you think?

[sacha777]

I have another question concerning Hawaii: why is the water temperature cooler than in the Caribbeans/Florida in summer?

[knocker]

Documented decrease in frequency of Hawaii's northeast trade winds

Scientists at University of Hawaii at Manoa (UHM) have observed a decrease in the frequency of northeast trade winds and an increase in eastern trade winds over the past nearly four decades, according to a recent study published in the Journal of Geophysical Research. For example, northeast trade wind days, which occurred 291 days per year 37 years ago at the Honolulu International Airport, now only occur 210 days per year.

http://www.eurekalert.org/pub_releases/2012-10/uoh-ddi101112.php

[sacha777]

That's interesting. So, I guess it means that the clime becomes drier?