Reference
Hawaii weather by month
Rainfall, air temperature and sea temperature for five stations, taken from NOAA rather than from anybody's impression of a holiday.
Almost every Hawaii guide, this one included, tells you the weather depends on which coast you are on. Here is that claim as a number.
Hilo receives 12.2 times the annual rainfall Kona does, and the two sit on the same island about 80 miles apart. That gap is larger than the gap between any two months of the year, anywhere in the state. Which coast you sleep on matters more than when you come.
Rainfall, inches per month
| Station | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| HonoluluOʻahu · leeward | 1.8 | 1.9 | 2.4 | 0.8 | 0.8 | 0.5 | 0.5 | 0.8 | 0.9 | 1.5 | 2.3 | 2.2 | 16.4 |
| KahuluiMaui · leeward | 2.4 | 2.0 | 2.6 | 1.3 | 0.7 | 0.2 | 0.5 | 0.5 | 0.5 | 0.8 | 1.8 | 2.8 | 16.2 |
| LīhuʻeKauaʻi · windward | 2.8 | 3.6 | 5.6 | 2.0 | 2.2 | 1.8 | 1.8 | 2.3 | 2.2 | 3.3 | 4.0 | 4.6 | 36.2 |
| KonaHawaiʻi Island · leeward | 1.4 | 1.2 | 1.0 | 0.6 | 0.6 | 0.8 | 0.5 | 0.5 | 0.5 | 0.9 | 0.8 | 1.1 | 9.9 |
| HiloHawaiʻi Island · windward | 7.9 | 10.2 | 12.7 | 9.4 | 7.0 | 7.3 | 9.2 | 11.3 | 8.7 | 10.2 | 14.4 | 12.1 | 120.4 |
Darker is wetter. The two Hawaiʻi Island stations are the same island: Kona on the dry side, Hilo on the wet one.
Mean air temperature, Fahrenheit
| Station | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Honolulu | 74 | 74 | 75 | 77 | 78 | 80 | 82 | 82 | 82 | 80 | 78 | 76 |
| Kahului | 73 | 73 | 74 | 76 | 77 | 79 | 81 | 81 | 81 | 79 | 77 | 75 |
| Līhuʻe | 72 | 72 | 73 | 75 | 76 | 78 | 80 | 80 | 80 | 79 | 76 | 74 |
| Kona | 75 | 75 | 76 | 77 | 78 | 80 | 81 | 82 | 81 | 80 | 78 | 76 |
| Hilo | 71 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 77 | 76 | 74 | 72 |
The range across a whole year is about nine degrees. Hawaii does not really have seasons in the way the mainland does, and this is what that looks like as data.
Sea temperature, Fahrenheit
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 77 | 76 | 77 | 77 | 78 | 79 | 80 | 81 | 81 | 81 | 79 | 78 |
Coolest in February at 76, warmest from August to October at 81. The whole annual range is five degrees, which is why nobody in Hawaii talks about the water being cold.
Annual rainfall where people stay
| Area | Island | Inches per year | NOAA station |
|---|---|---|---|
| Kohala coast, Waikōloa | Hawaiʻi Island | 8.5 | USC00519144 |
| Kailua-Kona | Hawaiʻi Island | 9.9 | USW00021510 |
| Ko Olina | Oʻahu | 16.9 | USC00510248 |
| Kauaʻi west, Waimea | Kauaʻi | 17.8 | USW00022501 |
| Waikīkī | Oʻahu | 20.7 | USC00519397 |
| Līhuʻe and the east side | Kauaʻi | 36.2 | USW00022536 |
| Kailua and Kāneʻohe | Oʻahu | 50.9 | USC00513117 |
| North Shore, Haleʻiwa | Oʻahu | 52 | USC00519603 |
| Princeville and Hanalei | Kauaʻi | 75.2 | USC00518165 |
| Volcano Village | Hawaiʻi Island | 96.2 | USC00511303 |
| Hilo | Hawaiʻi Island | 120.4 | USW00021504 |
| Upper Mānoa valley | Oʻahu | 151 | USC00516128 |
The five stations above are the standard reference set. These are the resort areas people actually book, which is a different question and a wider spread: Kohala coast, Waikōloa takes 8.5 inches a year and Upper Mānoa valley takes 151, a factor of 17.8. Upper Mānoa is listed because it sits five miles from Waikīkī and takes seven times the rain, not because anyone should stay there.
Methodology
- Rainfall and air temperature: NOAA NCEI Monthly Climate Normals, 1991 to 2020. Thirty-year averages, the same figures the National Weather Service quotes. Station IDs: Honolulu USW00022521, Kahului USW00022516, Līhuʻe USW00022536, Kona USW00021510, Hilo USW00021504.
- Annual rainfall by area: same dataset and same 1991 to 2020 window, read from the station nearest each resort area rather than from the five reference stations. Where the nearest gauge is some distance from the area it stands for, the station column says so. Station IDs: Waikīkī USC00519397, Ko Olina USC00510248, Kailua and Kāneʻohe USC00513117, North Shore, Haleʻiwa USC00519603, Upper Mānoa valley USC00516128, Kauaʻi west, Waimea USW00022501, Līhuʻe and the east side USW00022536, Princeville and Hanalei USC00518165, Kohala coast, Waikōloa USC00519144, Kailua-Kona USW00021510, Volcano Village USC00511303, Hilo USW00021504.
- Sea temperature: NOAA CO-OPS station 1612340, Honolulu. Computed here from 34,802 hourly observations, 2021 to 2024, since NOAA retired its own coastal water temperature guide in May 2025.
Using this page
Quote it, screenshot it or link it. A credit to hawaiitravelers.com/climate is appreciated and not required. If a figure here stops matching its source, tell us and it gets recomputed and re-dated rather than quietly edited.
This is one of four measured pages. The closest companion is Hawaii drive times, measured the same way and for the same reason: the other half of what an itinerary quietly assumes. For the one Hawaii number that changes by the hour rather than by the decade, there is the live volcano status.
What these numbers mean for a specific trip is in the month-by-month guide, and each month has its own page with the local detail.
Download as CSV: month by month or annual rainfall by area, two of six datasets published as files. Both carry the NOAA station id, so any figure can be checked at source.