Honolulu weather in September: Honolulu, Hawaii: normal highs, lows, rain and records for September
Honolulu in September has a normal high of 88°F and a normal low of 75°F, a daily mean of 82°F, holding near 88°F all month. Measurable precipitation falls on 7 days in a normal September, 0.88 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 31°C and low of 24°C, 22 mm of precipitation in September.
- NOAA stationHonolulu International Airport
- Station IDUSW00022521
- Location21.32°N 157.93°W
- Elevation7 ft (2 m)
- From the center5 miles
- Population (census place)344,967
- Jan 81° 67°
- Feb 81° 67°
- Mar 81° 68°
- Apr 83° 70°
- May 85° 72°
- Jun 87° 74°
- Jul 88° 75°
- Aug 89° 76°
- Sep 88° 75°
- Oct 87° 74°
- Nov 84° 72°
- Dec 82° 69°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Honolulu in September?
The normal high is 88°F and the normal low 75°F, for a daily mean of 81.6°F. September is 0.6°F cooler than August and 1.2°F warmer than October. September is the 2nd warmest month of the year in Honolulu and the 7th wettest. Across the month the normal high falls 1°F, from 89°F on September 1 to 88°F on September 30. From one year to the next September's mean temperature typically moves about 1.1°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 81°F and 83°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 24%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 89°F | 75°F | 21% | 6% |
| September 8 | 89°F | 75°F | 23% | 7% |
| September 15 | 88°F | 75°F | 23% | 7% |
| September 22 | 88°F | 75°F | 24% | 8% |
| September 30 | 88°F | 75°F | 24% | 8% |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 1, coldest night September 27)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 89°F | 75°F | 21% | 6% | 12 h 30 min |
| September 2 | 89°F | 75°F | 22% | 6% | 12 h 30 min |
| September 3 | 89°F | 75°F | 22% | 6% | 12 h 30 min |
| September 4 | 89°F | 75°F | 22% | 7% | 12 h 30 min |
| September 5 | 89°F | 75°F | 22% | 7% | 12 h 30 min |
| September 6 | 89°F | 75°F | 22% | 7% | 12 h 30 min |
| September 7 | 89°F | 75°F | 22% | 7% | 12 h 30 min |
| September 8 | 89°F | 75°F | 23% | 7% | 12 h 30 min |
| September 9 | 89°F | 75°F | 23% | 7% | 12 h 20 min |
| September 10 | 89°F | 75°F | 23% | 7% | 12 h 20 min |
| September 11 | 89°F | 75°F | 23% | 7% | 12 h 20 min |
| September 12 | 89°F | 75°F | 23% | 7% | 12 h 20 min |
| September 13 | 89°F | 75°F | 23% | 7% | 12 h 20 min |
| September 14 | 89°F | 75°F | 23% | 7% | 12 h 20 min |
| September 15 | 88°F | 75°F | 23% | 7% | 12 h 20 min |
| September 16 | 88°F | 75°F | 23% | 7% | 12 h 20 min |
| September 17 | 88°F | 75°F | 24% | 7% | 12 h 20 min |
| September 18 | 88°F | 75°F | 24% | 7% | 12 h 10 min |
| September 19 | 88°F | 75°F | 24% | 7% | 12 h 10 min |
| September 20 | 88°F | 75°F | 24% | 7% | 12 h 10 min |
| September 21 | 88°F | 75°F | 24% | 8% | 12 h 10 min |
| September 22 | 88°F | 75°F | 24% | 8% | 12 h 10 min |
| September 23 | 88°F | 75°F | 24% | 8% | 12 h 10 min |
| September 24 | 88°F | 75°F | 24% | 8% | 12 h 10 min |
| September 25 | 88°F | 75°F | 24% | 8% | 12 h 10 min |
| September 26 | 88°F | 75°F | 24% | 8% | 12 h |
| September 27 | 88°F | 75°F | 24% | 8% | 12 h |
| September 28 | 88°F | 75°F | 24% | 8% | 12 h |
| September 29 | 88°F | 75°F | 24% | 8% | 12 h |
| September 30 | 88°F | 75°F | 24% | 8% | 12 h |
- Normal high
- 88°FSeptember average
- Normal low
- 75°FSeptember average
- Precipitation
- 0.88 inmonth total
- Days with precipitation
- 70.01 inch or more
- Days at 90°F or more
- 9
- Daylight
- 12 h 30 min to 12 hSeptember 1 to September 30
- Days at 70°F or more
- 30
- Days at 80°F or more
- 30
- Sunshine
- 88%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00022521; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Honolulu in September?
On a given September day the chance of 0.01 inch or more is 23% on average, highest around September 28 (24%). In all, 0.88 in falls on 7 days of a normal September.
In a normal September in Honolulu, 9 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00022521.
How humid and windy is Honolulu in September?
At 3 p.m. the normal temperature is 86°F with 55% relative humidity and a dew point of 68°F; at 6 a.m. it is 76°F with 78% humidity. The wind averages 9.7 mph, most often from the east-northeast in the afternoon. A dew point of 65°F or more feels muggy to most people.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 76°F | 68°F | 78% | 6.3 mph | 59% |
| 9 a.m. | 82°F | 68°F | 64% | 9.8 mph | 47% |
| noon | 86°F | 68°F | 55% | 13.5 mph | 35% |
| 3 p.m. | 86°F | 68°F | 55% | 13.9 mph | 36% |
| 6 p.m. | 81°F | 68°F | 64% | 11.6 mph | 38% |
| 9 p.m. | 79°F | 69°F | 71% | 8.9 mph | 56% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00022521. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for September in Honolulu?
The warmest September temperature on Honolulu's official record (since 1940) is 95°F, on September 19, 1994; the coldest is 64°F, on September 22, 2019. The wettest September brought 4.48 in (2015).
The September mean against the 1991-2020 normal of 81.6°F: 2021 81.6°F (at normal), 2022 82.0°F (+0.4), 2023 82.4°F (+0.8), 2024 82.3°F (+0.8), 2025 82.5°F (+1.0), 2026 82.8°F (+1.2). 5 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 81.6°F | at normal | 0.12 in |
| 2022 | 82.0°F | +0.4°F | 0.43 in |
| 2023 | 82.4°F | +0.8°F | 0.10 in |
| 2024 | 82.3°F | +0.8°F | 0.06 in |
| 2025 | 82.5°F | +1.0°F | 0.71 in |
| 2026 | 82.8°F | +1.2°F | 1.16 in |
Source: records: ACIS, NWS threaded record HNLthr; recent months: ACIS, station USW00022521. Records and recent months use complete months only.
How does September in Honolulu compare across Hawaii?
Across the 18 places PlainClimate covers in Hawaii, September normal highs run from 75°F in Kula to 90°F in Kahului; Honolulu's is 88°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.