October 2024 was the wettest month in Chilliwack on the books since the record-breaking atmospheric river disaster of November 2021.
Conditions were generally mild and wet as El Nina transitioned into a weak La Nina, according to data recorded by Roger Pannett, volunteer weather observer Environment & Climate Canada, in Chilliwack.
It was during the weekend of Oct. 19 that the first atmospheric river of 2024 produced a four-day rainfall total of 114.8 millimetres. Unsettled conditions continued until month's end with heavy rain and strong winds at times.
With total precipitation for the month of October coming in at 259.3 mm it was a whopping 139.26 per cent above normal, Pannett said.
That made it the wettest October in 12 years and the wettest month since the record-breaking 615.6 mm in November 2021.
A series of Pacific frontal systems, moving on-shore, were the predominant weather feature for the month.
There was only one brief high pressure ridge with four warm and sunny days prior to mid month. Temperatures peaked at 21.9C,(6.5C above normal) 30 per cent relative humidity on Oct. 12, with a cool overnight low temperature of 4.0C (1.8C below normal) on Oct. 25.
Mean temperatures for October were 0.9 C above normal, (standard deviation + or – 1.1C) primarily due to the regular mild and moist on shore south westerly air flow. It was the 18th consecutive month with above normal temperatures, including 11 months in excess of the monthly standard deviation, based on 1951 to 1980 averages.
Chilliwack's year-to-date precipitation totals are 1,167.1 mm on 144 days compared to the 30-year average of 1,346.7 mm on 133 days.
