Quick Facts About Hawai'i
- Rainfall in Hawai'i is decreasing.
- The annual temperature in Hawai'i is rising.
Climate Change in Hawai'i
In Hawai‘i, annual average temperatures over the past century show a statistically significant warming trend, although both warming and cooling periods occurred. Based on a representative network of weather stations throughout the islands, this figure shows the difference in annual average temperature as compared to the average during 1944–1980 (this period was selected as the baseline because it has the greatest number of index stations available), with red bars showing years with above average temperatures and blue bars showing years with below average temperatures. As temperature continues to rise across the region and cloud cover decreases in some areas, evaporation is expected to increase, causing both reduced water supply and higher water demand.
Source: University of Hawai‘i at Mānoa, Department of Geography and Environment.
Decreasing Rainfall
Along with rising temperatures, the island of Hawai’i is facing decreasing rainfall.
The main islands of Hawai‘i have more than 1,000 native plant species, and many of these are vulnerable to future climate shifts. Projections under a higher scenario (RCP 8.5) suggest that by the end of the century, the current distributions of more than 350 native species will no longer be in their optimal growing climate range.