June 2026 Monthly Rainfall Summary for Hawaii

Monthly Precipitation Summary 

State of Hawaii 

Month: June 2026

Prepared: July 6, 2026

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

Averages used in this summary have switched to the 1991-2020 values where available.

State: [Text data table for rain gages]

Headline: Typical summer rainfall distribution with windward and mauka areas generally above average and leeward areas below average for the month of June.

June began with a period of wetter-than-normal trade wind weather as a weak surface trough moving in from the southeast brought elevated moisture on the 1st and 2nd. Moderate trade winds focused the heaviest rainfall over windward and mauka areas, while a slight southeast wind component enhanced showers across the Kaʻū and Puna Districts of the Big Island and the south slopes of Haleakalā on Maui. Rainfall totals generally ranged from 3 to 5 inches, with isolated amounts of 7 to 10 inches along the Hāmākua and Kaʻū coasts of the Big Island. Flooding closed a portion of Highway 11 between Kāwā and Honuʻapo in Kaʻū.

A more typical early summer trade wind pattern returned from the 3rd through the 10th, with moderate to locally breezy easterly winds and scattered windward and mauka showers. Trade winds weakened into the light to locally moderate range through the 16th, allowing localized land and sea breezes to develop over the more wind-sheltered areas. Rainfall remained limited overall, although a brief increase in trade wind speeds on the 14th and 15th produced a modest uptick in windward and mauka showers.

Light easterly winds continued on the 17th and 18th as another weak surface trough increased low-level moisture. Shower coverage briefly expanded, especially across windward portions of the Big Island, Maui, and Oʻahu. Minor flooding also occurred along Kūhiō Highway near Hāʻena on Kauaʻi.

Drier and more stable conditions returned through the 22nd under light to moderate east-southeast winds. While rainfall was generally limited, light winds and dew points in the lower 70s produced warm, muggy conditions across the smaller islands on the 19th and 20th before slightly drier east-northeast flow provided some relief.

Moderate to breezy trade winds returned for the final week of the month. A surface trough passing westward through the islands and weak upper-level instability brought a modest increase in windward and mauka showers through the 25th. Thereafter, breezy trades persisted with a return to a typical pattern of scattered trade wind showers through the end of June.

Island of Kauaʻi : [June 2026 map] [year-to-date map]

Rainfall this month concentrated over the central higher elevations, as well as extending north and south to the central coasts. Only five sites across the island managed to come in above average for June, with the rest of the windward areas near to just below average (70 to 100%) and leeward areas well below average (50% or less). For the third month in a row, the USGS gage on Mt. Waiʻaleʻale had the highest monthly total for the island and the state with 36.69 inches (111% of average), and the highest daily total for the island with 5.41 inches on the 2nd. 

The year to date (YTD) totals and percentages of average were still near to above average again this month, but less so than at the end of May, as the impact of the significant late-winter rainfall fades. The highest YTD total still belongs to Mt. Waiʻaleʻale with 247.90 inches (132% of average).

Island of Oʻahu: [June 2026 map] [year-to-date map]

Rainfall was focused along the Koʻolau Mountains for June (typical for summer), with less overall rainfall than May, but still above the June average for most sites in that area. Remaining areas of the island saw comparatively little rainfall, hovering around 40 to 80% of average for the month. The Mānoa Lyon Arboretum Ua Net site had the highest total for the month with 18.05 inches, (140% of average) and the highest daily total of 4.90 inches on the 2nd. The Honolulu Airport tied their record daily rainfall of 0.04 inches on the 2nd (last set in 2003).

The year to date (YTD) totals continue to run well above average for all reporting stations, most likely due to this island receiving the highest rainfall amounts during the March storms. The highest YTD total came from the USGS Moanalua RG with 134.28 inches (208% of average). 

Maui County: [Maui June 2026 map] [year-to-date map] [Molokaʻi/Lanaʻi June 2026 map] [year-to-date map]

The typical summer windward rainfall focus is clearly seen across Maui County in June, with all of those sites above average. Even with less overall rainfall than their windward counterparts, most other areas of the islands still came in above average for the month, with the exception of leeward Molokai and West Maui (around 60% of average). The USGS Puʻu Kukui gage had the highest monthly total in the county with 36.55 inches (125% of average), as well as the highest daily total of 6.31 inches on the 2nd. This site also recorded its wettest June since 2005 (missing data in 2015 and 2025). Other sites recording their wettest June include: Kīhei Ua Net (since 1993 – missing data in 2017, 2023), Kepuni Gulch USGS (record since 2010), Makapulapai RAWS (since 2003 – missing data in 2019), and W. Wailuaiki Stream (since 2016). Kahului Airport set two daily rainfall records in June: 0.07 inches on the 2nd (old record 0.04 inches last set in 1960) and 0.27 inches on the 15th (old record 0.06 inches set in 1986).

The year to date (YTD) totals for all reporting sites in the county were still near to above average (around 100 to 300%). The highest YTD total was at Puʻu Kukui with 207.18 inches (108% of average). 

Island of Hawaiʻi: [June 2026 map] [year-to-date map]

The windward coast and upper slope areas, as well as much of the Puna and Kaʻū Districts, fared the best in June, with well above average rainfall in most spots. Much of the Kona and Kohala District coast and slopes, as well as the interior higher elevations, came in below average. The most notable of these sites were Kaloko-Honokōhau and Kona Airport, with 14% and 5% of their June averages, respectively. The USGS site at Saddle Road Quarry had the highest monthly total for the island with 26.82 inches (322% of average), as well as the highest daily total for the island and statewide of 10.00 inches on the 2nd. Eleven sites had their wettest June on record: Hakalau RAWS (since 2004), Honokaʻa Ua Net (since 1991 – missing data in 1996, 1999), Kapāpala Ranch Ua Net (since 1999), Kapāpala RAWS (since 2012), Keaumo RAWS (since 2012), Kealakomo RAWS (since 2010), Nēnē Cabin RAWS (since 2015), Pali 2 RAWS (since 2003), Puʻu Mali RAWS (since 2015), and Pāhala Ua Net (since 1991). Additionally, the Hilo Airport set two daily rainfall records in June: 3.00 inches on the 1st (old record 1.39 inches set in 2015) and 1.99 inches on the 10th (old record 1.17 inches set in 2002).

The year to date (YTD) totals were still mostly near to above average for the island, though a few spots in leeward South Kohala District were below average (60-80%). The highest YTD total was the USGS gage at Honoliʻi Stream with 154.86 inches (140% of average).

Data Sources: Data used in this report are from National Weather Service sources including climate network weather observation stations at Līhuʻe, Honolulu, Kahului, and Hilo, the Ua Net network of automated rain gages, and selected Cooperative Observer sites. Additional data come from automated rain gages operated by the State of Hawaiʻi Department of Land and Natural Resources, the U.S. Geological Survey (USGS), 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, as well as manual observations from the Community Collaborative Rain, Hail, and Snow Network (CoCoRaHS). Averages come from the National Centers for Environmental Information (1991-2020 series) and the Rainfall Atlas of Hawaiʻi (https://www.hawaii.edu/climate-data-portal/hawaii-climate-atlases/). Supplemental data used in some of the analyses are from the Hawaiʻi Climate Data Portal (https://www.hawaii.edu/climate-data-portal/). Data presented here are not certified and should be used for informational purposes only. 

Tina Stall
Senior Service Hydrologist 
NOAA/NWS Weather Forecast Office Honolulu