June 2016 Precipitation Summary

State of Hawaii

MONTH: June 2016

PREPARED: July 6, 2016

Note:  This summary uses the arithmetic mean, or average, for “normal” rainfall values.

State: [Text data table for rain gages]

Trade winds, mainly in the moderate to fresh intensity range, persisted throughout the month of June across the main Hawaiian Islands. The only weakness occurred on June 4 and 5 where light trade winds allowed land and sea breezes to dominate local conditions. Throughout most of the month, abundant showers embedded within the trade winds produced wet conditions over the windward slopes. Fortunately, shower intensities were mostly in the light to moderate range and did not persist for long periods of time over specific locations which helped prevent serious flooding problems. The wet spring conditions in the island chain were similar to spring 1998 which, like 2016, was also the ending phase of a strong El Nino event.

The most notable rain event during the month occurred from June 12 through June 17 as unstable conditions from an upper level low pressure system enhanced showers along the windward slopes of the Big Island. Rainfall totals ranged from 6 to over 14 inches during the 6-day period but produced just minor flooding problems.

Island of Kauai : [June 2016 map] [year-to-date map]

Rain gages on the windward side of Kauai recorded near to above average rainfall totals while many of the low-lying leeward gages posted below average totals for the month of June. The U.S. Geological Survey’s (USGS) Mount Waialeale gage had the highest monthly total of 44.31 inches (135 percent of average), which marked the wettest June since 2005. This site also had the highest daily total of 4.11 inches on June 20.  The northwestern slopes of the island had very wet conditions as well with the Kokee, Kilohana, and Waiakoali gages all receiving between two to three times the average rainfall for June. Kokee’s 6.54 inches (296 percent of average) broke the record for the highest June rainfall total at this site. Wainiha’s 13.14 inches (182 percent of average) checked in as the highest June total since 1996.

Wet spring conditions have erased much of the rainfall deficits from the winter months though several leeward locations were still in the below average range for 2016 through the end of June. Mount Waialeale had the highest year-to-date total of 154.80 inches (82 percent of average), which was also the second highest total in the state.

Island of Oahu: [June 2016 map] [year-to-date map]

Most of the rain gages on Oahu logged near to above average rainfall totals for the month of June. The exceptions were mainly on the leeward areas of the Waianae Range with mostly below average monthly totals from Lualualei to Makua Valley. The Manoa Lyon Arboretum gage had the highest monthly total of 17.78 inches (150 percent of average) and the highest daily total of 3.22 inches on June 9. This monthly total marked the wettest June since 1998 at this location.

Despite the wet spring, rainfall totals at most of the rain gages across Oahu were in the below average range for 2016 through the end of June. The USGS’ Poamoho No. 1 gage had the highest year-to-date total of 76.37 inches (69 percent of average).

Maui County: [Maui June 2016 map] [year-to-date map] [Molokai/Lanai June 2016 map] [year-to-date map]

Rain gages on the slopes of Haleakala had monthly totals mostly in the near to above average range while most sites on the slopes of the West Maui Mountains had totals in the near to below average range. The USGS’ West Wailuaiki gage had the highest monthly total of 30.96 inches (237 percent of average) and the highest daily total of 4.79 inches on June 6. The Kahakuloa gage (5.92 inches, 359 percent of average) on the windward side of the West Maui Mountains posted its highest June total since 1993. On east Maui, Hana Airport (6.30 inches, 146 percent of average) had its wettest June since 2005.

Rainfall totals for 2016 through the end of June remained in the below average range at many of the locations in Maui County due to the significant rainfall deficits built during the early months of the year.  The West Wailuaiki year-to-date total of 167.33 inches (138 percent of average) remained the highest in the state.

Island of Hawaii: [June 2016 map] [year-to-date map]

Most of the rainfall totals on the Big Island were in the near to above average range for the month of June. Locations with below average monthly totals were mainly in the North Kona District. The USGS’ Saddle Road Quarry gage had the highest monthly total of 30.69 inches (368 percent of average) and the highest daily total of 3.89 inches on June 14. This gage recorded more than an inch of rain on 12 days during the month and 14.53 inches during the period from June 12 through June 17. The Piihonua, Waiakea Uka, and Mountain View gages all recorded their highest June totals since 1997 and Hilo Airport had its wettest June since 1998. Kahua Ranch (6.21 inches, 154 percent of average) had its highest June total in a data record going back to 1992.

Although spring 2016 was very wet for much of the Big Island, rainfall totals through the end of June were in the below average range at most locations due to the large deficits built during the early months of the year.  The Saddle Road Quarry gage had the highest year-to-date total of 123.26 inches (177 percent of average).

Data Sources: Data used in this report are largely from National Weather Service sources including climate network weather observation stations at Lihue, Honolulu, Kahului, and Hilo, the Hydronet state network of automated rain gages, and selected Cooperative Observer sites.  Additional data come from automated rain gages operated by the State of Hawaii Department of Land and Natural Resources, the U.S. Geological Survey, the U.S. Bureau of Land Management, the U.S. National Park Service, the Department of Defense, the U.S. Fish and Wildlife Service, and the U.S. Department of Agriculture.  Averages come from the National Climatic Data Center (1981-2010 series) and the Rainfall Atlas of Hawaii (http://rainfall.geography.hawaii.edu/).  Data presented here are not certified and should be used for informational purposes only.

Kevin R. Kodama
Senior Service Hydrologist
NOAA/NWS Weather Forecast Office Honolulu