Climate averages 1991–2020

Honiara weather
in September.

A hot, very wet month: the 9th warmest and the 4th driest of the year.

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

Average high 29.3°C Daytime mean, September

Average low 25.1°C Night-time mean, September

Rainfall 209 mm 25 days with ≥1 mm

Daylight 12 h Sunrise to sunset, per day

September is a hot month in Honiara: daytime highs average 29.3°C and nights cool to about 25.1°C. By daytime temperature it is the 9th warmest of the 12 months.

Expect about 209 mm of rain on roughly 25 days, which makes September a very wet month (the 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 03 min on an average September day.

From September to October, average highs rise by 0.1°C to 29.5°C, and monthly rainfall rises from 209 mm to 271 mm.

The annual picture

September 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

Honiara climate table

1991–2020

Monthly climate averages for Honiara, 1991–2020
Month	Average highHigh / low	Average low	Rainfall mm/month	Rain days ≥1 mm/day	Daylight hours/dayDaylight h/day
January	29.7°C25.4°C	25.4°C	365	28.4	12.613 h
February	29.5°C25.4°C	25.4°C	350	26.3	12.412 h
March	29.5°C25.3°C	25.3°C	366	28.6	12.212 h
April	29.6°C25.3°C	25.3°C	301	27.4	11.912 h
May	29.5°C25.4°C	25.4°C	228	27.1	11.712 h
June	29.2°C25.4°C	25.4°C	172	24.8	11.612 h
July	28.9°C25.2°C	25.2°C	203	25.2	11.612 h
August	29.0°C25.0°C	25.0°C	189	24.9	11.812 h
September, selected	29.3°C25.1°C	25.1°C	209	24.6	12.012 h
October	29.5°C25.1°C	25.1°C	271	27.3	12.312 h
November	29.7°C25.2°C	25.2°C	287	26.8	12.513 h
December	29.8°C25.3°C	25.3°C	337	27.7	12.713 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 Honiara) is explained once on the Honiara year overview and on the Sources, method and limits page.