City of Chilliwack July 2021 Weather Report – The Driest on Record

Chilliwack – The City of Chilliwack July 2021 Weather Report confirms that this was the Driest on Record. (Data recorded by Roger Pannett, Volunteer Weather Observer for Environment Canada at Chilliwack).

Variable	July 2021	30 Year Average
Mean Maximum	28.36 °C	24.3C
Mean Minimum	15.31 °C	12.01C
Mean Temperature	21.84 C	18.2 C
Rainfall	0.0 mm	46.0 mm
Snowfall	0.0 cm	0.0 cm
Total Precipitation	0.0 mm	46.0 mm
Days of Rain	0 days	6 days
Days of Snow
Total Days of Precipitation	0 days	6 days
Frosts
Relative humidity average	62.15 %	.

With a blocking ridge of high pressure, entrenched over western Canada, the hot & dry conditions since mid June continued throughout July.

Temperature extremes for the month were a hot 36.5 °C (+11.1°C) with a 25% relative humidity on July 30^th and an average overnight minimum of 11.5°C on July 22^nd.

Three overnight high minimum temperature records were observed:-

Date. New Record. Previous Record.

July 1^st. High min 18.6°C (+7.8°C). 17.8°C in 2013.

July 2^nd. “ “ 18.9°C ( +7.8°C). 18.5°C in 2015.

July 31^st. “ “ 20.7 °C( +8.7°C). 18.9°C in 1907.

There were 8 hot days, with temperatures exceeding 30.0°C, compared to the average 3 hot days with a + or – 2.7 day deviation.

With a mean temperature at 21.84°C (3.64°C above normal), after 2015 and 2018, it was the 3^rd hottest July on record. It was the 10^th consecutive July with mean temperatures above normal, the past nine in excess of the standard deviation + or – 1.2°C, a warming trend never previously observed since Chilliwack records commenced in 1895.

Extreme UV. levels were reported on 3 days, peaking at a 12 rating on July 15^th.

The drought, which started in mid June, continued throughout July totaling 46 days and tied as the second longest on record. (51 day drought during the summer of 1951 & 46 day drought during the summer of 1985.)

Since mid month the Fire Danger Rating ,as issued by the B.C. Wildfire Service, is being reported as,’Extreme,’ in the Lower Mainland in addition to Interior regions & the majority of Vancouver Island.

At 0.0 mm it was the driest July on record. (The previous driest July was in 1960 with a trace of precipitation.) Since July 2020, monthly precipitation totals have been below normal, a trend not previously observed during the past > 32 years!

The City of Chilliwack 2021 precipitation total to date remains at 546,3 mm on 87 days compared to the average of 983 mm on 97 days.