Chilliwack weather for the month of April 2024 continued to be milder than usual with less precipitation.
There were no weather records broken in April but at the very end of the month Chilliwack saw its first April thunderstorm with hail since 2017.
“Throughout April, a predominantly zonal jet stream, with its associated pacific frontal systems, resulted in rainy or showery conditions on 15 days,” according to Roger Pannett, Chilliwack volunteer weather observer for Environment and Climate Change Canada in his April 2024 weather report.
It was the fifth consecutive April with precipitation measuring at below normal, a trend not seen since 1934, his report noted, and the 22nd consecutive month with total precipitation below normal, a trend not seen since 1879.
The precipitation total to date is 552.2 mm on 70 days for 2024, compared to the average of 760.8 mm on 68 days.
It was “an unstable air mass” that produced the first April thunderstorm activity, with hail, since 2017, Pannett stated.
In general the transient high-pressure ridges produced “a limited number of warm, sunny days.”
The month ended with cool, and moist conditions as active low pressure frontal systems moved onshore or stuck close to southern B.C. It was on April 30 that the rare thunderstorm with hail rolled in.
Temperature extremes for the month included the 22.4C (5.7C above average) and a very low 19 per cent relative humidity on April 23, and the 0.5C (3.6C below normal) with a ground frost on April 17.
No records were broken, but the 2024 spring season in Chilliwack has experienced the earliest last frost on record, on
March 7. Prior to this year, the earliest last frost was March 8, and the average date of last air frost in Chilliwack is on April 6.
With mean temperatures for April at 1.08C above normal (standard deviation + or -1.1C), it was the mildest April since 2021 and the twelfth consecutive month with above normal temperatures, based on the 1951 to 1980 averages.