Chilliwack – Environment Canada data recorded by Roger Pannett, Volunteer Weather Observer for Environment Canada at Chilliwack.
The mild & rainy conditions of late January continued into the first week of February as a series of Pacific frontal systems continued to move onshore.
|Variable||February 2021||30 Year Average|
|Mean Maximum||5.99 C||8.1 C|
|Mean Minimum||0.37 C||1.2 C|
|Mean Temperature||3.18 C||4.7 C|
|Rainfall||106.0 mm||177.8 mm|
|Snowfall||10.6 cm.||17.0 cm|
|Total Precipitation||116.6 mm||194.8 mm|
|Days of Rain||19 days||15 days|
|Days of Snow||6 days||3 days|
|Total Days of Precipitation||22 days||17 days|
|Relative humidity average||68.76 %||.|
On February 8th, following a mild first half of winter, a transition to much colder conditions developed. A deep upper level trough, coupled with the Polar vortex shifting westwards from central Canada, initiated a push of arctic air southwards through the Province. Arctic outflow warnings were issued and experienced February 10th to 12th as rising surface pressures over the B.C Interior produced frigid temperatures in the strong and gusty north east winds. On February 11th, temperatures fell to -9.8 ⁰C (10.2 ⁰C below normal) with a wind chill of -20.0 ⁰C and the coldest temperature of the winter. Two record cold temperatures occurred: –
February 10th record low max at -4.5 ⁰C (11.9 ⁰C below average). Previous record low max – 4.4 ⁰C in 1922.
February 11th record low mean at -7.65 ⁰C (11.45 ⁰C below normal). Previous record low mean -7.3 ⁰C in 1922.
With close proximity to the Arctic front on a few days light flurries occurred. However, with relative humidity down to 25%, snowfall in the eastern Fraser Valley was minimal. As temperatures moderated and the relative humidity increased, a 4.4 cm snowfall occurred on February 15th.
After mid-month generally mild, damp conditions returned to the Fraser Valley. On February 21st, in strong and gusty south west winds and showers, temperatures peaked for the month at 12.9 ⁰C (4.6 ⁰C above normal).
On February 22nd, a record high minimum of 9.1 ⁰C (8.3 ⁰C above normal) occurred. The previous record high minimum was 6.5 ⁰C in 1992 & 2012.
During the early morning of February 25th, with a low freezing level, there was a 4.0 cm snowfall.
With mean temperatures 1.52 ⁰C below normal, temperatures for four of the past five February’s have been below normal. An unusual trend. However, 2020/21 winter mean temperatures were 4.44 ⁰C, 1.28 ⁰C above the average 3.16 ⁰C and the mildest since the winter of 2015/16.
Continuing the > 30-year trend of milder winters, T Sum 200 occurred early on February 14th, 2021, compared to the March 10th average.
For the 4th consecutive February, precipitation totals were below normal.(-40.14%.)
The 2021 total precipitation to date is 335.2 mm on 40 days compared to the 30-year average of 458.5 mm on 36 days.
Total winter 2020/21 precipitation is at 567.1 mm on 60 days compared to the average of 752.9 mm on 58 days. This includes the winter snowfall of 43.8 cm, 58% below normal.