Hilo weather in September
September in Hilo: hot, soaked, with clean air — a great time to visit.
#3 of 12 months in Hilo · #406 of 604 destinations to visit in September · comfort 72/100 (tier B)
Updated June 2026 · climate normals from ERA5 reanalysis
Hilo climate normals — September
| Daytime high | 27°C / 80°F | 🥵 hot |
|---|---|---|
| Nighttime low | 22°C / 71°F | |
| Feels like (high) | 31°C / 88°F | |
| Rainfall | 189 mm / 7.4 in | ⛈ soaked |
| Rainy days | 26 days | |
| Humidity | 83% | 💦 very humid |
| Dew point | 20°C / 69°F | |
| Sunshine | 11.3 h/day | |
| Daylight | 12.2 h | |
| Wind | 18 km/h / 11 mph | |
| Air quality (US AQI) | 19 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Where is Hilo?
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Hilo in September — FAQ
- Is September a good time to visit Hilo?
- September in Hilo: hot, soaked, with clean air — a great time to visit. It ranks #3 of 12 months for Hilo on SeasonMap's comfort score (72/100).
- What is the weather like in Hilo in September?
- In September, Hilo averages a daily high of 26.7°C and a low of 21.5°C, with about 189 mm of rain over roughly 26 rainy days.
- What is the air quality in Hilo in September?
- Hilo has a mean US Air Quality Index of about 19 in September.