but be prepared for fluctuations says Environment Canada meteorologist
There is a joke about the weather in various Canadian locations, in which the punchline states: ‘If you don’t like it, wait an hour and it will change.’
Formulaic translation into an equivalent ‘funny’ on climactic change is not however as simple as extending the timeframe.
Anecdotally, this winter’s lack of ice fishing opportunities, maple syrup tapping timing and experiencing a thunder hailstorm while boiling sap in February provides some indication of historically unusual southern Ontario conditions. Accurately quantifying that within appropriate context is however considerably more complicated.
‘Weather’ recognizes day-to-day locational fluctuations explains Environment and Climate Change Canada Meteorologist Gerald Cheng. ‘Climate change’ instead happens over both an extended time period and wider geographical range. “Not just one station.”
Complicating the process further is the reality equipment has changed over the extended timeframe required for a data set applicable to changes in climate. One needs to ‘clean the noise’ says Cheng, additionally interpreting data as accurately as possible through a broader, holistic approach.
“It’s suggestive but not conclusive,” he said. “We still have to dig further. “We want to ensure what we see, is.”
One can pull historical 1961-1990 and 1991-2020 data on monthly normals recorded through the Delhi weather station, compare them to each other and add monthly 2022 and 2023 numbers and 2024, through to April 11th. And while they’ll be interesting and possibly include indications of a trend or two, they will unfortunately not provide a definitive roadmap for southern Ontario farmers facing the 2024 growing season.
“When you look in and drill down you will see fluctuation,” said Cheng. “And fluctuation is what you have to deal with.”
To a layman’s untrained eye, comparing the graphed data from 30-year averages between 1961 and 1990; and 1991 and 2020 indicates temperatures have gone up roughly a degree between the two time periods while precipitation has levelled out slightly month to month.
For interest and to illustrate the fluctuations Cheng speaks of compared to 30-year averages, the 2022, 2023 and early 2024 numbers break down as follows:
2022 Precipitation Average High Low Median Temperatures
January 46.5 mm -3.0 -13.9 -8.4
February 92.3 0.5 -9.8 -4.6
March 63.8 5.8 -3.5 -1.2
April 61.1 12.3 0.9 6.6
May 63.6 21.3 8.9 15.1
June 80 25.6 12.4 19.0
July 56.7 27.1 14.5 20.9
August 58.2 27.0 14.4 20.7
September 75 22.0 10.7 16.3
October 36.9 16.0 0.1 9.5
November 35.3 9.8 -0.1 4.9
December 67.1 2.6 -3.6 -0.5
2023 Precipitation Avgerage High Low Median Temperatures
January 89 mm 2.0 -3.6 -0.8
February 74 3.4 -5.8 -1.2
March 144.1 4.7 -3.8 0.5
April 117 14.4 2.5 8.4
May 30.2 20.7 4.8 12.8
June 83.3 24.9 11.8 18.3
July 157.6 26.5 15.1 20.8
August 79.9 24.5 13.0 18.7
September 76.8 23.0 11.3 17.2
October 63.3 16.2 6.8 11.5
November 51.3 8.5 -2.1 3.2
December 76.5 5.7 -0.3 2.7
2024 Precipitation Average High Low Median Temperatures
January 152.7 mm 0.2 -5.2 -2.5
February 44.7 5.2 -9.8 0.0
March 62.3 8.7 -3.5 3.6
To April 11 31 13.3 0.9 7.8
Thirty-year averages tend to smooth things out. However, of note, for example, is January precipitation of 46.5 mm in 2022 compared to roughly twice that in 2023 (89 mm), and again roughly, three times the 2022 value in the first month of this year (152.7 mm). Temperatures also exhibited similar discrepancies, average lows of -13.9, -3.6 and -5.2 respectively for those three month-long periods.
The fluctuations also illustrate the impossibility of making weather predictions based on historical numbers. There is also significant variance with the percentage predictions based even on the best possible forward-looking data.
For example, Environment Canada predictions suggest a 53 per cent chance temperatures will be above normal through April, May and June of this year, in this area.
“However, what you’re asking is what about the other 47 per cent?” Cheng continued.
Predictions for ‘near normal’ temperatures come in at 32 per cent he said, below normal at 14 per cent. “It gives you a signal, but it doesn’t rule out possibilities for other scenarios.”
Similarly, there is a 36 per cent prediction for above normal precipitation through the three-month period, a 34 per cent possibility of normal values and a 31 per cent chance of below normal, a roughly equal division.
Weather station data does provide valuable short and longer-term insights into both weather and climate. “But it takes time to arrive at what that means.”
And in conclusion, while it would be wonderful for farmers to have access to a definitive three-month outlook, the more realistic approach is to include a healthy helping of positive outlook and operational flexibility matching weather’s invariable fluctuations. “I think we have to be prepared,” Cheng concluded, “that’s really the message.”.
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