OBSERVATION
It seems to me that winters in Toronto are starting later and lasting longer with not much of a spring. This year we have a very mild winter with above seasonal temperatures but winter lasted all the way to mi-April. In fact, we got more snow in the first 2 weeks of April than in any other month this winter. In April we got over 20 cm of snow as compared to only 3 cm in December and 10 cm in January. Then the weather changed and on April 18th temperatures in Toronto reached 24 C. There appears to be a trend that has developed over several decades where winter starts later and lasts right up until summer.
As can be seen in the charts below, there seems to be a warming trend for the months of April and May since 1940. The increase in average temperatures for the months of April and May over the past 60 years ranges from 4ºC to 6ºC which is significantly greater than the increase in average global temperature which, according to a recent IPCC's report, increased by 0.74ºC over the last century. (Intergovernmental Panel on Climate Change, Climate Change 2007: Synthesis Report Summary for Policymakers). This makes me wonder if the spring months are starting to become warmer and feel more like summer. Therefore we get the impression that we go right from winter to summer.
BACKGROUND
Temperature trends from 1940 to 2010 recorded at the TORONTO LESTER B. PEARSON INT'L Airport, Weather Station. Source of records - Environment and Climate Change Canada
Mean Temperatures for the Month of April since 1940 – Weather Station: TORONTO LESTER B. PEARSON INT'L Airport in ONTARIO
Month Mean Monthly Temperature (C)
April 1940 4.1
April 1950 3.4
April 1960 7.5
April 1970 6.6
April 1980 6.2
April 1990 8.3
April 2000 6.7
April 2010 10.5
Source: Ministry of Environment and Climate Change Website
Mean Temperatures for the Month of May since 1940 Weather Station: TORONTO LESTER B. PEARSON INT'L Airport in ONTARIO
Month Mean Monthly Temperature (C)
May 1940 11.7
May 1950 12.3
May 1960 13.6
May 1970 12.0
May 1980 13.8
May 1990 11.6
May 2000 14.3
May 2010 16.0
Source: Ministry of Environment and Climate Change Website
If this observation is an actual trend that is occurring ecosystems must adapt to this sudden change in seasons which will help some thrive while others may not be able to adapt due to the rapid change.
Consultant/Expert Comment
Jane Liu - Assistant Professor University of Toronto - April 22, 2016
"I am happy to write some comments on the air temperature data that you collected from the Ministry of Environment and Climate Change website. I think your tables on the historic temperature in April and May at Toronto are accurate. The source of the data is well indicated. The information is clear with titles and units. The tables clearly show a warmer spring in the recent years."
Observations From Members 