<img class="styles__noscript__2rw2y" src="https://s.w-x.co/util/image/w/hawaii4.jpg?v=at&w=485&h=273" srcset="https://s.w-x.co/util/image/w/hawaii4.jpg?v=at&w=485&h=273 400w, https://s.w-x.co/util/image/w/hawaii4.jpg?v=ap&w=980&h=551 800w" > The orange boxes show the days that daily record highs were tied or broken this month in Honolulu.

At a Glance Honolulu has tied or broken daily record highs on 9 of the first 18 days in June.

Numerous record highs have been set in Honolulu and other parts of Hawaii since mid-May.

Warmer-than-average sea-surface temperatures are playing a role in the record-breaking temperatures. Honolulu, Hawaii, has experienced a string of record-breaking high temperatures since mid-May, including a tie of its all-time June high temperature earlier this month.

Daily record highs have been tied or broken in Honolulu on 9 of the first 18 days in June, including a tie of the monthly record of 92 degrees on June 10. Temperature records in the city date back to 1890.

Five additional daily record highs were tied or broken in the second half of May.

The record high temperatures set in Honolulu this month have only been about 2 to 5 degrees above the June average high of 87 degrees.

But since Hawaii is in the open Pacific Ocean, highs even a few degrees above the daily average can clinch records. That's because the Pacific Ocean keeps temperatures from fluctuating very much in the lower elevations of Hawaii throughout the year.

<img class="styles__noscript__2rw2y" src="https://s.w-x.co/util/image/w/sst-anomalies-1.jpg?v=at&w=485&h=273" srcset="https://s.w-x.co/util/image/w/sst-anomalies-1.jpg?v=at&w=485&h=273 400w, https://s.w-x.co/util/image/w/sst-anomalies-1.jpg?v=ap&w=980&h=551 800w" > Darker orange shadings represent sea-surface temperatures that are the farthest above average in the central Pacific Ocean on June 16, 2019. (TropicalTidbits.com)

Warmer-than-average sea-surface temperatures in the central Pacific Ocean are one factor in Hawaii's record-breaking temperatures since mid-May, according to the National Weather Service (NWS).

You can see this in the darker orange shadings near the Hawaiian Islands in the map above, which shows sea-surface temperatures compared to average on June 16. An occasional disruption in trade winds is also to blame for the record streak.

Honolulu hasn't been the only city in the island chain to see record-breaking temperatures. Lihue on Kauai and Kahului on Maui have also broken several high temperature records since mid-May.

Kahului tied or set new daily records on 20 of 23 days from May 18 through June 9. This includes new all-time monthly record highs for May (96 degrees on May 22) and June (95 degrees on June 6-7). Weather records in Kahului date back to 1954.

The hottest temperature ever recorded in Hawaii was a 100-degree reading on April 27, 1931 at Pahala on the Big Island, according to NOAA.