Climate averages 1991–2020

Honolulu weather
in August.

A warm, very dry month: the 2nd warmest and the 3rd driest of the year. Meets the pleasant-weather rule

Long-term climate patterns, not a forecast for a particular trip.

Average high 27.7°C Daytime mean, August

Average low 24.5°C Night-time mean, August

Rainfall 9.9 mm 2 days with ≥1 mm

Daylight 13 h Sunrise to sunset, per day

August is a warm month in Honolulu: daytime highs average 27.7°C and nights cool to about 24.5°C. By daytime temperature it is the 2nd warmest of the 12 months.

Expect about 9.9 mm of rain on roughly 2 days, which makes August a very dry month (the 3rd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 52 min on an average August day.

Among the 498 cities listed in the United States, Honolulu ranks joint 341st of 498 for the warmest August highs and 113th of 498 for the driest August (rainfall, lowest first). The mean August high of those 498 cities is 29.9°C; Honolulu is 2.2°C cooler than that mean.

From August to September, average highs rise by 0.1°C to 27.8°C, and monthly rainfall rises from 9.9 mm to 10 mm.

The annual picture

August in context

30-year average

Average highAverage low°C

Monthly rainfall

Average total · mm

Averages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated

Every month, side by side

Honolulu climate table

1991–2020

Monthly climate averages for Honolulu, 1991–2020
Month	Average highHigh / low	Average low	Rainfall mm/month	Rain days ≥1 mm/day	Daylight hours/dayDaylight h/day
January	24.3°C21.3°C	21.3°C	37	4.9	11.011 h
February	24.1°C21.0°C	21.0°C	29	4.5	11.411 h
March	24.3°C21.2°C	21.2°C	39	4.4	12.012 h
April	25.0°C21.9°C	21.9°C	11	2.4	12.613 h
May	26.0°C22.7°C	22.7°C	13	2.2	13.113 h
June	26.8°C23.6°C	23.6°C	8.0	1.1	13.413 h
July	27.3°C24.1°C	24.1°C	5.9	1.0	13.313 h
August, selected	27.7°C24.5°C	24.5°C	9.9	1.8	12.913 h
September	27.8°C24.5°C	24.5°C	10	2.2	12.312 h
October	27.3°C24.2°C	24.2°C	20	2.9	11.712 h
November	26.1°C23.4°C	23.4°C	40	4.9	11.111 h
December	25.0°C22.3°C	22.3°C	47	5.1	10.911 h

Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.

Read the numbers correctly

Climate, not a promise.

These patterns help compare months. They cannot tell you the weather on a specific day of your trip.

Sources, method and limits

How these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Honolulu) is explained once on the Honolulu year overview and on the Sources, method and limits page.