Weather in Hilo in September 2025
Average weather
Average temperature in Hilo in September
The expected average maximum temperature in September is +82°F with a maximum of +84°F and a minimum of +68°F.
The average maximum temperature goes up 0% by the end of the month, compared with the beginning of the month, from +82°F to +82°F.
Is Hilo warm or cold in September?
Hilo is typically warm in September.
Maximum temperatures go up compared to the previous month from +82°F to +82°F. The minimum temperature also goes up from +72°F to +72°F.
It’s generally warm, but pack a long-sleeve shirt for evenings.
September is one of the warmest months in Hilo, here is the comparison with other months:
Climate in Hilo in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +82°F | +82°F | +82°F | ||||
| Min. temperature | ||||||
| +66°F | +66°F | +64°F | ||||
| Max. temperature | ||||||
| +90°F | +93°F | +91°F | ||||
| Rainfall | ||||||
| 283 mm | 240 mm | 264 mm | ||||
| Wind | ||||||
| 2 m/s | 2 m/s | 2 m/s | ||||
| Humidity | ||||||
| 79% | 79% | 80% | ||||
| Air pressure | ||||||
| 1015 HPa | 1015 HPa | 1015 HPa | ||||
| Sunny days | ||||||
| 0 | 1 | 1 | ||||
| Cloudy days | ||||||
| 1 | 1 | 2 | ||||
| Rainy days | ||||||
| 30 | 28 | 29 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
September weather is still as ok as in August. The temperature levels stay the same in the area of +82°F for average maximum temperature during the day. As September arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 283 mm to 240 mm. Humidity levels don’t change as the month goes on, averaging around 79%. The average wind speed doesn’t change much during September, staying around 2 m/s. The good news is there are likely to be more sunny days in September, from 0 to 1.
October brings much the same weather, it remains ok.
Wind
The average wind speed is 2 m/s getting up to 3 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in Hilo is gradually increasing during September, going from 2 m/s to 2 m/s over the course of the month.
Rain
How was the weather last September in Hilo?
Climate Change Over the Years
The climate in Hilo in September has not changed that much over the last 43 years.
The average temperature was the lowest in 1999 (+79°F) and the highest in 2015 (+83°F). The driest year was 1983 with only 1515 mm of rainfall, and the wettest year was 1990 with 6234 mm.
FAQ
Is September a good time to visit Hilo?
Can you sunbathe in Hilo in September?
Is Hilo rainy in September?
Is it sunny in Hilo in September?
Other cities in USA
Monthly weather in Hilo
Source of the data
For this page, we’ve looked at the typical weather in Hilo, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.
