I took a look at the daily temperature records for the record-holding town (Lytton BC at 49.6C) and the nearby town of Merritt BC (max 46.0C) using the GHCN daily data from the 1960's, Merrtt has a continuous record from 1969 to 2019 but that for Lytton is split into several sites
What is interesting is that this period at the end of June for both sites is well off the hottest period of the year on average. They are both usually about 4C cooler now than between Mid July and Mid August so presumably if this synoptic pattern had occurred later in the year it could easily have topped 50C at Lytton at least
I tried to calcuate return periods for these temperatures on the basis that the daily history is a normal distribution (but it is hard to tell exactly)
By detrending the data I looked at both the return period now and what it would have been without Global Warming since the 1960's
For the current temperature regime the return period in the hottest period of the year is beteeen 130-150 years and without Global Warming it is 380-560 years
In this part if the world the hottest period has warmed by about 1.5C since 1969
For this to occur outside the hottest period of the year (as it has in this case) the return periods are 750-790 years and without warming 4600-15000 years
Originally Posted by: lanky