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:

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.

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.

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.