Honolulu Weather in September
United States · Tropical climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
September in Honolulu sees average temperatures ranging from a low of 23.4°C (74.1°F) to a high of 29.3°C (84.7°F), with a mean of 25.8°C (78.4°F). Compared to the annual average of 24.1°C (75.4°F), this month is 1.7°C warmer than the yearly norm. Precipitation averages 15.5mm, making it approximately 23.0mm drier than the monthly average of 39.0mm. This is the driest month of the year, with just 15.5mm of precipitation. The city receives an average of 11.6 hours of sunshine per day during September, with relative humidity averaging 69.8%. Wind speeds reach an average maximum of 22.5 km/h. For travelers, this month offers a temperature experience in Honolulu, with drier-than-average conditions compared to the rest of the year.
Honolulu sounds like a year-round summer, but the rain patterns matter. I packed for beaches in November and got three wet days — the windward side gets 4x the rain of Waikiki. The sweet spot is April-May: 26°C, low rain, fewer tourists. December-March brings the big surf and whale season, plus occasional showers. Pack reef-safe sunscreen (mandatory by law), rash guard for snorkeling, and a light rain shell for windward trips. Summer (June-August) is hotter and more humid but trade winds keep it manageable. Skip spring break crowds in March — Waikiki gets packed.
September vs Adjacent Months
| Metric | August | September | October |
|---|---|---|---|
| Mean Temp | 25.8°C (78.4°F) | 25.8°C (78.4°F) | 25.2°C (77.4°F) |
| Rainfall | 24.2mm | 15.5mm | 31.1mm |
| Sunshine | 12.5 hrs | 11.6 hrs | 10.7 hrs |
| Humidity | 69.3% | 69.8% | 73.1% |
| Wind | 24.0 km/h | 22.5 km/h | 20.3 km/h |
| Rainy Days | 16.0 | 17.0 | 20.2 |
Seasonal Context
September falls in Autumn in the Northern Hemisphere. Autumn sees temperatures gradually cooling from summer highs. For travelers visiting Honolulu in September, the data indicates favorable conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Honolulu in September?
The average temperature in Honolulu during September ranges from 23.4°C (74.1°F) to 29.3°C (84.7°F), with a mean of 25.8°C (78.4°F).
How much does it rain in Honolulu in September?
Honolulu receives an average of 15.5mm of precipitation in September, spread across approximately 17.0 rainy days. This is the driest month of the year.
What should I pack for Honolulu in September?
Based on September weather data, pack lightweight, breathable clothing, sunscreen, and a hat.
Is September a good time to visit Honolulu?
September is a good time to visit Honolulu, with comfortable temperatures and manageable rainfall.
Other Months for Honolulu
Cities with Similar September Climate (Tropical)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 21.31°, -157.86°. Timezone: Pacific/Honolulu. Last updated: 2026-07-30.