Recently we were breathlessly warned that Ottawa was rocketing up the lists for most days over 30° C. Yes, folks, in early July the nation’s capital shot from 79th to 68th place with 60th in sight. And by late July it was all the way up to 29th place. But the odd thing is that the top 5 years were all… (in ascending order) 1911, 1949, 1921, 1955 and 1876. Spot the pattern? Nor could we.
Famously, if you generate a set of readings using random numbers, even simply flipping a coin, you get pseudo-patterns, like those apparent paths in the woods that peter out after a few meters or tens of meters. Sometimes heads are on a roll, coming up eight times in 10. Sometimes tails. But for that reason a few hot years is not a trend (nor are a few cool ones) even if they’re not linked to some non-climate-related cause like an El Nino.
If someone throws dice a dozen times and gets seven every time, you might start wondering if they possibly tampered with them. And if you really did get a reliable pattern where the years kept getting hotter with minor fluctuations, you could reasonably suggest that something was going on, though even then you’d have to do a more plausible job of filtering out natural cycles than the computer models that just assume they don’t exist. But when you’re breathlessly closing in on a temperature record from 1921, it means the square root of nothing at all. Especially if 3rd place is held by 1916, 4th by 1955, 5th by 2018 and 6th by 1887. It’s the sort of thing you’d get from a monkey throwing darts.
Then there’s the hype. For instance back on Canada Day BC set several records for high temperature. But you probably didn’t hear much about them because Vancouver’s record was for the lowest high temperature on Canada Day since 1960, just 14.8 °C, the average being 21. Now imagine if Vancouver had broken the previous high with a temperature seven degrees above average.
In Chilliwack it was even more remarkable: the high of 13.5 °C was the lowest in recorded history, a term here meaning “in 139 years”. Which got us curious, so we had a look around. Seems that if you go east from Chilliwack, which is now essentially a suburb of Vancouver, into the B.C. interior, Summerland and nearly Kelowna, the town whose mayor blamed the 2017 flooding and wildfires on climate change, also both set records in June. Also for low daily highs. Kelowna’s 12.8° C high on June 14 beat the 1912 record by over 2 degrees, while Summerland shaved half a degree off its 1912 record.
Then we checked the average temperatures for neighboring Washington State since 1895 and found that the hottest by a whole degree was 2016. But in 2nd place was 1934 and in 3rd 1958 whereas 1915 was the coldest, 1955 2nd and 1985 3rd. 2018 was also quite warm, nearly as warm as 1940. But after 2015 temperature plunged and 2019 was less than half a degree above the long-term average. What does it all mean? That weather is variable.