Honolulu, HI weather in September
September in Honolulu: hot and humid, with some rain. Highs 88°F, lows 75°F, rain on about 7 days.
- Normal high
- 88°F
- Normal low
- 75°F
- Wet days
- 7
- 0.9 in total
- Muggy days
- 27
- dew point 65°F+
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 89°F | 88°F |
| Normal low | 75°F | 75°F |
| Chance of a wet day | 22% | 24% |
| Sunrise / sunset | 6:14 am / 6:47 pm | 6:22 am / 6:20 pm |
| Daylight | 12.6 h | 12.0 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Hawaii time (no daylight saving)).
A typical September day
- 6 am76°Fdew point 68°F
- 9 am82°Fdew point 68°F
- Noon86°Fdew point 68°F
- 3 pm86°Fdew point 67°F
- 6 pm82°Fdew point 68°F
- 9 pm79°Fdew point 68°F
NOAA hourly normals (local standard time) from Honolulu Intl Airport (5 mi away); average wind 10 mph; clear or few clouds in 37% of daytime hours, mostly cloudy or overcast in 23%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F0 of 30
- Beach dayshigh 80-95°F, under 0.05 in of rain, afternoon wind under 15 mph15 of 30
- Hot dayshigh 90°F or more9 of 30
- Muggy daysdaily mean dew point 65°F or more27 of 30
- Wet daysat least 0.01 in of rain or melted snow7 of 30
- Notable rainat least 0.10 in2 of 30
- Freezing nightslow 32°F or below0 of 30
Average days per September, counted from daily records for each year 1991-2020.
Rain in September
Normal precipitation is 0.9 in; a dry September brings about 0.3 in and a wet one about 1.0 in (25th and 75th percentiles). Days with half an inch or more are rare.
How September varies from year to year
- Warmest September, 1991-20201995: average high 91°F
- Coolest September2012: average high 86°F
- Wettest September2015: 4.5 in
- Driest September1998: 0.05 in
- Highest reading95°F (September 19, 1994)
- Lowest reading64°F (September 22, 2019)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
September compared with August and October
| August | September | October | |
|---|---|---|---|
| Normal high | 89°F | 88°F | 87°F |
| Normal low | 76°F | 75°F | 74°F |
| Wet days | 6 | 7 | 8 |
| Comfortable days | 0 | 0 | 0 |
| Daylight | 12.8 h | 12.3 h | 11.7 h |
Highs change by -1°F from August and -1°F into October.
Nearby alternatives in September
- Cooler: Hilo, HI210 mi · high 83°F · 23 wet days
How Honolulu ranks in September
- Normal high90th warmest of 378 cities; 2nd of 7 in Hawaii
- Wet days150th driest of 378
- Comfortable days340th most of 342
What to pack for Honolulu in September
- Light, breathable clothing – highs near 88°F and about 27 muggy days
- A swimsuit – about 15 beach days
Heating and cooling
September has 0 heating degree days and 498 cooling degree days (base 65°F), 10% of the year's total heating and cooling demand.
Questions
How hot is Honolulu in September?
The normal high is 88°F and the normal low is 75°F. From 1991 to 2020 the hottest September reading was 95°F (September 19, 1994).
Does it rain a lot in Honolulu in September?
About 7 days in September have at least 0.01 in of precipitation, and the normal total is 0.9 in. The wettest September in 1991-2020 was in 2015 (4.5 in); the driest was in 1998 (0.05 in).
Is September a good time to visit Honolulu?
September ranks 12th of 12 months on our comfort score for Honolulu (46 out of 100). It has almost no comfortable days and about 9 days at 90°F or hotter. The best months are February, March and June.
Where the numbers come from
- Temperature, rain, frost dates, humidity and wind by hour and cloud cover: Honolulu Intl Airport (USW00022521), 4.7 mi WNW of the city center, 7 ft . NOAA normals and daily records, 1991-2020.
- Snowfall and snow depth: Beretania Pump Stn 705 (USC00510211), 0.3 mi E of the city center, 20 ft . NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Honolulu International Airport (911820-22521), 5.3 mi WNW of the city center, 6 ft . Hourly observations, 1991-2020.