People who live near North Battleford, Sask., say they have never seen a drier spring than this one.
The March through May period was the driest since records were first kept 70 years ago, said Environment Canada senior climatologist David Phillips.
The area received 11 millimetres of precipitation, significantly down from the normal level of 70 mm.
But the strange thing, weather-wise, is that last year was the wettest on record for the same time period and location, when nearly 200 mm of rain fell. It’s that increased variability that frustrates farmers, policy makers and climatologists.
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“The big story for agriculture is the fact that the growing season has been less predictable, less dependable,” Phillips said.
He checked June-August data on the Prairies for the last 63 years and calculated the top 10 wettest and top 10 driest years. He found twice the number of “weird and wild” extremes in the past 10 years than he would have expected.
“This is what drives farmers off the deep end,” he said.
The atmosphere becomes turbulent and chaotic as it looks for a plateau and a way to stabilize. The weather becomes unpredictable.
“You can’t blame growers for not heeding the advice of so-called experts,” Phillips said.
Climate change, on the other hand, is a more gradual process to which farmers and others can adapt.
That change is lengthening the growing season.
“We find a significant increasing trend in the length of the growing season and in the associated available heat,” said an article published in the April 2010 Journal of Applied Meteorology and Climatology, which analyzed data from 1895 to 2007 to determine long-term agroclimatic trends.
“The winter temperature is less damaging and the frost-free periods are longer.”
Phillips recently provided data on frost-free periods that should have been more accurately described as freeze-free. Frost-free is the date between, on average, the last spring frost and first fall frost. Freeze-free calculates when the mean temperature stays above the freezing mark.
“Freeze-free and frost-free will both be longer (as a result of the changing climate),” Phillips said.
The normal frost-free period in Saskatoon from the 1880s to 1910 was 117 days. It climbed to 121 days during the following 30-year period and 126 days between 1950 and 1980.
Phillips said the figure is now likely around 130 frost-free days, compared to 164 freeze-free days.
However, the frost-free season is also increasing, and models suggest it could be 145 days by the 2020s.
