It’s a small heat wave, nothing too record-breaking. In fact, we probably will at most be 5 degrees away from any sort of highest temperature record. Even if it isn’t too big of a heat wave, I can still write about it!
The reason for this heat wave, is, very surprisingly a heat dome. That doesn’t usually happen at this time of year. The thing is, it’s staying far to the south; maybe only brushing Canada’s border a tiny bit. We’re only catching the edge of this system, and if you go all the way down to something like Lethbridge, Monday, Tuesday, and Wednesday all have good chances at 25. Since we’re only getting the topmost affected areas of the blocking high, and it is bordered by cold waves on either side, it’s only going to actually be noticeably “hot” or “very hot” on Monday and Tuesday.
For the actual temperature values, Monday is probably a high of 21, though it could land as low as 19, or as high as 22. (that 19 is very unlikely, by the way) Tuesday is more like a 22, but it could be as low as 20, or as high as 25. If you’ve already packed your summer gear away, or you’re not a fan of the heat, then don’t worry about that 25. It is something like a 5-10% chance of that actually happening; that’s really low.
If you were wondering what is coming after this heat, then wonder no longer. We’re going to be quickly heading right back down to average and maybe even below average. The rest of the week is probably mid-to-low teens for highs, except for Friday, where it’s more like a “close to 10” Oh yes, and really good chances of frost Wednesday and Thursday night.