July 2020 Weather In Review – After Record Cool Start – Mother Nature Was Back To (Near) Normal

August 2, 2020

Fraser Valley (with files from Roger Pannett, Volunteer Weather Observer for Environment Canada) – July 1st gave us a record cool Canada Day (remember the rain?) and the first of what was supposed to be a Party in the Park Friday, was not festive at all.

Then things went back to “near normal”.

Data recorded by Roger Pannett, Volunteer Weather Observer for Environment Canada at Chilliwack, B.C.

Variable	July 2020	30 Year Average
Mean Maximum	25.11 °C	24.3C
Mean Minimum	14.21 °C	12.01C
Mean Temperature	19.66 C	18.2 C
Rainfall	39.7 mm	46.0 mm
Snowfall	0.0 cm	0.0 cm
Total Precipitation	39.7 mm	46.0 mm
Days of Rain	7 days	6 days
Days of Snow
Total Days of Precipitation	7 days	6 days
Frosts
Relative humidity average	67.06 %	.

With an unusually active low-pressure system, in Alberta, and associated moisture spiraling westwards into B.C, July 1^st, Canada Day, was wet & cool. With a record cool maximum temperature of 13.5 ⁰C (9.4 ⁰C below normal) it was the coolest July 1^stin > 139 years. The previous record cool max was 14.4 ⁰C in 1966.

After mid-month, high pressure ridges were the dominant weather feature. Sunny days and warming temperatures, day and night, occurred. There were 6 hot days, with temperatures exceeding 30.0°C, compared to the average 3 hot days with a + or – 2.7day deviation.

Beneath clear overnight skies, on July 5^th, temperatures dipped to 10.5 ⁰C, the coolest July night in 7 years. After mid-month warm nights prevailed. On July 21^st there was a record high minimum of 17.2 ⁰C (5.5 ⁰C above normal). The previous high minimum was 16.2 ⁰C in 2015.

For the month, mean temperatures were 1.46 °C above normal. It was the 9^th consecutive July with mean temperatures above normal, the past eight in excess of the standard deviation + or – 1.2°C, a warming trend never previously observed since Chilliwack records commenced in 1895. Also, it was the 9^th consecutive month with above average mean temperatures.

On July 27^th, temperatures peaked for the month at 34.7°C (9.5 °C above normal with a 25 % relative humidity.)

Due to the predominantly dry conditions, after mid-month, total rainfall for July was 13.7% below normal.

The City of Chilliwack 2020 precipitation total to date is 884.7 mm on 118 days compared to the average of 983 mm on 97 days.