Climate averages 1991–2020

Nanaimo weather
in September.

A mild, moderately wet month: the joint 3rd warmest and the 5th driest of the year.

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

Average high 18.8°C Daytime mean, September

Average low 12.5°C Night-time mean, September

Rainfall 86 mm 9 days with ≥1 mm

Daylight 13 h Sunrise to sunset, per day

September is a mild month in Nanaimo: daytime highs average 18.8°C and nights cool to about 12.5°C. By daytime temperature it is the joint 3rd warmest of the 12 months.

Expect about 86 mm of rain on roughly 9 days, which makes September a moderately wet month (the 5th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 39 min on an average September day.

The nearest other city in this atlas is Vancouver (60 km away). In September its highs average 18.6°C, about as warm as Nanaimo, with 125 mm of rain.

Among the 86 cities listed in Canada, Nanaimo ranks joint 65th of 86 for the warmest September highs and joint 46th of 86 for the driest September (rainfall, lowest first). The mean September high of those 86 cities is 19.8°C; Nanaimo is 0.9°C cooler than that mean.

From September to October, average highs fall by 5.8°C to 13.1°C, and monthly rainfall rises from 86 mm to 177 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

Nanaimo climate table

1991–2020

Monthly climate averages for Nanaimo, 1991–2020
Month	Average highHigh / low	Average low	Rainfall mm/month	Rain days ≥1 mm/day	Daylight hours/dayDaylight h/day
January	5.9°C2.0°C	2.0°C	253	18.5	8.79 h
February	6.9°C2.2°C	2.2°C	150	14.8	10.110 h
March	8.9°C3.5°C	3.5°C	178	17.6	11.912 h
April	11.9°C5.8°C	5.8°C	123	15.2	13.714 h
May	16.1°C9.5°C	9.5°C	85	12.1	15.315 h
June	18.8°C12.4°C	12.4°C	69	10.6	16.116 h
July	22.1°C15.1°C	15.1°C	43	7.3	15.816 h
August	22.3°C15.3°C	15.3°C	54	6.3	14.414 h
September, selected	18.8°C12.5°C	12.5°C	86	9.3	12.713 h
October	13.1°C8.2°C	8.2°C	177	15.2	10.811 h
November	8.4°C4.4°C	4.4°C	264	18.7	9.29 h
December	5.6°C2.0°C	2.0°C	247	18.6	8.38 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.

Compare places

September in nearby cities

Distance from Nanaimo

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 Nanaimo) is explained once on the Nanaimo year overview and on the Sources, method and limits page.