At the end of every winter season people will ask, “What’s the spring weather going to be like this year”?
Even those of us who work in the Landscape industry want to know what we can expect weather-wise over the next couple of months, so we can plan & schedule our seasonal work. Long-term seasonal projections can offer only a general guideline, with very little real practical information; “warmer than usual”, or “slightly rainier”, for instance, but no real details or specific answers.
It is left to a careful statistical analysis of past spring seasons (let’s limit it to just April & May) to provide a better understanding of what our “typical” springs have been like over the past “X” number of years; and use that information to offer up a glimmer of expectations for the season ahead.
So what do the numbers actually show us?
The Environment Canada graph above provides 30 years of accumulated data for average monthly temperatures, as well as daily highs and lows, and precipitation totals. Obviously, our focus is on the “practical” spring months of April & May.
In this graph, precipitation also includes snowfall, which has historically occurred during April but very rarely in May. We see daily highs of +12ºc and +19ºc, and lows of +1ºc and +6ºc for the two months in question, while the average monthly temperature for April is +6ºc and for May it is +13.5ºc.
The precipitation totals are fairly close, 75 mm on average for April and 80 mm for May.
This gives us a pretty good starting point for understanding what we can expect for most springs. Now let’s examine some more recent monthly spring data for 2014-2018.
Once again, we have used Environment Canada statistics to provide the data in the following table:
The average daily temperatures for April and May are reasonably close to the earlier data, although there appears to be a greater variation in the amount of precipitation. I have also included the number of “rain days”. These are days that receive at least 1 mm of recorded precipitation.
So there you have it, our best prediction for what we can expect this spring (in my heart, all of June counts as summer!):
Let’s just wait and see what actually happens!
