Grand Finale: Winners and losers for the final weeks of summer

What you can expect for the final weeks of summer

The summer of 2019 has been remarkably unremarkable so far when you look at the national temperature pattern. While the warm weather season was slow to get started, July brought periods of hot and humid weather to most areas. So, when we look at the temperature pattern since June 1 (see map below) we see that most of Canada has been within a degree of normal so far during meteorological summer. Very few areas have seen a significant departure from normal.


The various shades of green, yellow and orange on the above map highlight areas that have been warmer than normal while the various shades of blue highlight the regions that have averaged out cooler than normal since June 1. The regions in white have been within a half degree of normal.

Looking ahead to the final weeks of the season, we expect a changeable pattern across much of Canada. Starting late this week and continuing through the end of next week a cooler pattern is expected to dominate much of Canada, especially from the Rockies to the Maritimes. The map below shows the dominant pattern for August 10 through 18.

LONGR Aug10-18

Often when part of Canada is cooler than normal, we will find a corresponding area that is warmer than normal (and vice versa), but that will not be the case during mid-August when there will be a noteworthy lack of heat across most of Canada. However, keep in mind that "normal" temperatures for mid-August are still near the highest we see all year, so most days will still be quite pleasant despite being a couple degrees cooler than normal.

This cooler pattern is expected to persist into late August across much of the Prairies with the potential for some unusually chilly weather at times, especially across Alberta. We will be closely watching to see whether this pattern will continue into September and threatens to bring an early end to the growing season.

LONGR EndofAugust

From the Great Lakes to the Maritimes, however, the upcoming period of cooler weather does not mark the end of warm summer weather for the year. Across this region, we expect a strong finish to summer with warmer than normal temperatures dominating again during the final 10+ days of August and continuing into early September.