Climate Insights for Duncan

Cowichan Valley Regional District, British Columbia, Canada

Hottest
August
23°C peak
Coldest
February
1°C low
Wettest
January
291mm rain
Best to Visit
July, August
Mild temps & low rain

Climate Overview

The climate in Duncan is cool. The average annual temperature is 9°C and approximately 1692mm of precipitation falls per year. January is the wettest month, receiving around 291mm of rainfall. Duncan is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, July, September. The coldest months are February, December, January, when temperatures can drop to 1°C. Snowfall occurs from January to December, with around 170cm accumulating over the season.

Temperature

10° 15° 20° 25° 30° Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Max: 6° Average: 3° Min: 2° Feb Max: 6° Average: 3° Min: 1° Mar Max: 9° Average: 5° Min: 2° Apr Max: 12° Average: 8° Min: 5° May Max: 17° Average: 12° Min: 8° Jun Max: 18° Average: 14° Min: 10° Jul Max: 22° Average: 16° Min: 12° Aug Max: 23° Average: 17° Min: 13° Sep Max: 19° Average: 14° Min: 11° Oct Max: 13° Average: 9° Min: 7° Nov Max: 9° Average: 6° Min: 4° Dec Max: 5° Average: 3° Min: 1°
Max
Average
Min

Temperatures in Duncan vary considerably across the year, with a 22°C difference between the coldest and warmest months. August is the warmest month, though highs remain moderate at 23°C with a mean of 17°C. February is the coolest month, with minimum temperatures around 1°C and an average of 3°C. Daily temperature variation is modest, with an average difference of 7°C between highs and lows. The sharpest temperature change occurs between September and October, with a 5°C shift in average temperatures.

Precipitation

0mm 50mm 100mm 150mm 200mm 250mm 300mm Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Precipitation: 291mm Snow: 41mm Feb Precipitation: 157mm Snow: 44mm Mar Precipitation: 163mm Snow: 24mm Apr Precipitation: 118mm Snow: 2mm May Precipitation: 47mm Snow: 0mm Jun Precipitation: 51mm Snow: 0mm Jul Precipitation: 21mm Snow: 0mm Aug Precipitation: 27mm Snow: 0mm Sep Precipitation: 118mm Snow: 0mm Oct Precipitation: 188mm Snow: 0mm Nov Precipitation: 278mm Snow: 12mm Dec Precipitation: 232mm Snow: 47mm
Precipitation
Snow

Duncan is a fairly wet location, receiving approximately 1692mm of precipitation annually, which averages out to around 141mm per month. The wettest month is January, averaging 291mm of rainfall. November and December also tend to see above-average precipitation. The driest month is July, with just 21mm. That's 269mm less than January, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic. Snowfall is a regular feature from January to December, with around 170cm accumulating over the season. December typically sees the most snow at around 47cm.

Wind

0km/h 5km/h Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Wind Speed: 2km/h Feb Wind Speed: 2km/h Mar Wind Speed: 2km/h Apr Wind Speed: 2km/h May Wind Speed: 2km/h Jun Wind Speed: 2km/h Jul Wind Speed: 2km/h Aug Wind Speed: 2km/h Sep Wind Speed: 2km/h Oct Wind Speed: 2km/h Nov Wind Speed: 2km/h Dec Wind Speed: 2km/h
Wind Speed

Duncan is relatively calm, with an average annual wind speed of 2km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is January, averaging 2km/h, though still comfortable for most outdoor activities. The calmest conditions occur in September, with average winds dropping to 2km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 0km/h between the calmest and windiest months.

Seasons

Winter
Dec 21
Spring
Mar 20
Summer
Jun 21
Autumn
Sep 23

92 days until Autumn

It is currently summer in Duncan, which began on June 21, 2026. Duncan is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in August at around 23°C, while the coldest stretch bottoms out in February near 1°C. Autumn is next, beginning on September 23, 2026 — 92 days from now.

Spring

Temperatures range from 2 to 17°C. Rainfall is heavy, totalling around 328mm across the season with a monthly average of 109mm. Winds are generally light, averaging 2km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.

Summer

Temperatures range from 10 to 23°C. Rainfall is relatively light, with around 100mm over the season and a monthly average of 33mm. Winds are generally light, averaging 2km/h. Comfortable clothing with a light layer for cooler evenings is all you need.

Autumn

Temperatures range from 4 to 19°C. Rainfall is heavy, totalling around 584mm across the season with a monthly average of 195mm. Expect around 12cm of snow accumulation during this period. Winds are generally light, averaging 2km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.

Winter

Temperatures range from 1 to 6°C. Rainfall is heavy, totalling around 680mm across the season with a monthly average of 227mm. Expect around 131cm of snow accumulation during this period. Winds are generally light, averaging 2km/h. Warm winter clothing and waterproof boots are a must, and travel may be affected by snow.

Best Time to Visit

Jan
Feb
Mar
Apr
May 12°
Jun 14°
Jul 16°
Aug 17°
Sep 14°
Oct
Nov
Dec

The best time to visit Duncan is during July and August, when the weather is most comfortable for travellers. During these months, average temperatures hover around 17°C with modest rainfall averaging 24mm per month. By contrast, February can be quite cold with temperatures dropping to 1°C. With minimal rainfall expected, you can pack light and plan outdoor activities with confidence.

Monthly Climate Data

The table below shows monthly climate averages for Duncan based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.

Month
Min Temperature
Max Temperature
Wind Speed
Precipitation
Snow
Jan
2 °C
6 °C
2 km/h
291 mm
41 cm
Feb
1 °C
6 °C
2 km/h
157 mm
44 cm
Mar
2 °C
9 °C
2 km/h
163 mm
24 cm
Apr
5 °C
12 °C
2 km/h
118 mm
2 cm
May
8 °C
17 °C
2 km/h
47 mm
0 cm
Jun Current
10 °C
18 °C
2 km/h
51 mm
0 cm
Jul
12 °C
22 °C
2 km/h
21 mm
0 cm
Aug
13 °C
23 °C
2 km/h
27 mm
0 cm
Sep
11 °C
19 °C
2 km/h
118 mm
0 cm
Oct
7 °C
13 °C
2 km/h
188 mm
0 cm
Nov
4 °C
9 °C
2 km/h
278 mm
12 cm
Dec
1 °C
5 °C
2 km/h
232 mm
47 cm
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