September was a more humid month in the Chemainus Valley compared to the levels of drought experienced in previous months, although still interspersed with many sunny days seasonally.
"The second half of the month saw some unusually wet conditions that produced a little more than four times the usual accumulated precipitation for the month," said Chris Carss, a volunteer weather observer / recorder for Environment Canada at his home in Chemainus.
September's total rainfall of 168.6 millimeters far exceeded the normal 40.8 millimeters.
It was the same story on Thetis Island, where Keith Rush noted a new September record being set at 131.4mm, breaking the previous high recorded at his Foster Point Road residence in 2018 of 99.6mm.
"September came in two distinct phases this year, as is often the case with the month as the main transition between summer and fall," Carss explained. โThe summer segment took up most of the first 13 days, but it wasn't always good summer weather. There were a few days that were sunny, hot, and dry, but almost as many were cloudy or partly cloudy with occasional rain.
โFor those who enjoy our warmer season, daily afternoon temperatures at least stayed in the low to mid-20s most of the time during the first half of the month. The summer weather ended on the 14th, eight days before the end of the astronomical summer on the equinox date of the 22nd. The afternoon temperatures were mostly teenagers, although a brief storm on the 19th led to a brief Indian summer. which lasted for a few days just as the astronomical summer was ending. "
With the seasonal drop in temperatures proceeding in a fairly normal fashion, overall daily temperatures remained within a half degree of normal for the month as a whole, Carss added.
The mean maximum of 19.4 degrees Celsius was not one degree below the normal of 20.1 C and the mean minimum of 11.8 C was slightly above the normal of 11.4 C.
The extreme maximum was 25.5 C on September 9 and the extreme minimum was 8.5 C on September 16.
"The other meteorological element that deviated significantly from normal in September was the number of sunny and dry days, which at 13 was five days less than normal," Carss said. "However, when additional partially sunny days are added that included some light rain, the total number of days with some sun increased to 20. If we take every day with any amount of rain, including cloudy or partially sunny days, That total comes to 14 days, including one with thunder, five more than the normal nine rainy days. To round the statistics, three days were cloudy and dry after the Indian summer ended. "
September has become a consistently colder and more autumnal month in recent years with weather summers starting earlier, Carss said.
โThis trend simply gives some additional legitimacy to the World Meteorological Organization definition of summer as early June to late August. Thus, the WMO definition states that summer begins a few days after Victory Day weekend and ends just before Labor Day weekend and back to school for most students. โ.
Despite heavy rains in September, Rush's total rainfall for the year to date on Thetis Island of 573.9mm is still well below last year's total at this time of 773.3mm.
October has started with normal temperatures, with variable clouds and it is expected to rain again this week.
"Rain frequencies and amounts are expected to remain close to normal until the end of the month, when the heaviest rains could move to mark the run-up to the central rainy season," Carss noted.
