Publication Date September 26, 2017

In Hawaii and the Pacific Islands, 2017 has been anything but normal

United States
Mean sea level trend for the Honolulu tide gauge station. Image: NOAA

Sea Level


The sea level anomalies recorded in Honolulu during May-August have been the highest ever, with observed values of 20 centimeters (8 inches) above normal in April, +17 centimeters (6.7 inches) during May, +9 centimeters (3.5 inches) in both June and July, and +10 centimeters (4 inches) in August.  Data from the Honolulu tide gauge shows the increasing trend in sea-level since 1905, with the recent events in 2017 above all others. 


Rainfall extremes

Abundant rainfall occurred throughout most of the U.S. Pacific island region during the first half of 2017, with almost all recording stations reporting above-average first-half totals.  It was one of the wettest spring periods on record in Pohnpei, and some flash flooding was even reported in American Samoa during May. 

However, rainfall patterns over the last three months of June, July, and August have been much drier than normal across the region.


Sea surface temperatures

Sea surface temperature data from NOAA’s Optimum Interpolation Sea-Surface Temperature (OISST) dataset indicate that many areas were warmer than normal across much of the Pacific during the first 8 months of 2017, with a small, localized region of cold anomalies now starting to develop along the equatorial eastern Pacific.