April through September offers the sunniest weather with calmer ocean conditions on the North Shore — ideal for boat tours and beach time. The North Shore sees its heaviest rainfall (and closes some roads) November through March, but the south and west sides stay relatively dry year-round. February through April is peak humpback whale season, and winter swells bring world-class surf to Hanalei. Shoulder seasons (April–May, September–October) offer thinner crowds and lower hotel rates.
| Month | High (°F) | Low (°F) | Notes |
|---|---|---|---|
| Jan | 70 | 60 | mild & changeable |
| Feb | 70 | 60 | mild & changeable |
| Mar | 70 | 60 | mild & wet |
| Apr | 71 | 61 | mild & wet |
| May | 73 | 63 | warm & wet |
| Jun | 75 | 65 | warm & wet |
| Jul | 76 | 66 | warm & wet |
| Aug | 76 | 66 | warm & wet |
| Sep | 77 | 66 | warm & wet |
| Oct | 76 | 66 | warm & wet |
| Nov | 73 | 64 | warm & wet |
| Dec | 71 | 62 | mild & wet |