Hawaii weather in August
The state broadly agrees with itself in August: afternoons run 90° in Kahului (Maui) and 83° in Hilo, with everywhere else in between.
Based on 5 weather stations. Five stations across four islands, all near sea level — the leeward-versus-windward difference shows up here, but upcountry and volcano-summit weather is another world these numbers don’t reach.
Oahu
Highs near 89°, nights around 76°, and 0.8 in of rain in a typical August.
| Place | Highs / lows | Wet days | The short version |
|---|---|---|---|
| Honolulu | 89° / 76° | 1 | Warmest month, and the day the trades quit you'll notice. |
Maui
Highs near 90°, nights around 72°, and 0.5 in of rain in a typical August.
| Place | Highs / lows | Wet days | The short version |
|---|---|---|---|
| Kahului (Maui) | 90° / 72° | 1 | Warm nights, warm water, and no reason to wear shoes. |
Kauai
Highs near 85°, nights around 75°, and 2.3 in of rain in a typical August.
| Place | Highs / lows | Wet days | The short version |
|---|---|---|---|
| Lihue (Kauai) | 85° / 75° | 5 | Warmest water of the year, and the calmest north shore. |
Big Island, Kona side
Highs near 87°, nights around 76°, and 0.5 in of rain in a typical August.
| Place | Highs / lows | Wet days | The short version |
|---|---|---|---|
| Kailua-Kona | 87° / 76° | 1 | The ocean hits its warmest — swimming stops being bracing. |
Big Island, Hilo side
Highs near 83°, nights around 70°, and 11.3 in of rain in a typical August.
| Place | Highs / lows | Wet days | The short version |
|---|---|---|---|
| Hilo | 83° / 70° | 18 | Heavy, humid, and green in a way photographs miss. |
Each place above has its own page for the full story — what the month feels like, what to pack, and whether the timing is right.