Climate Trends and Variations Bulletin - Spring 2021

Spring 2021 bulletin (PDF, 1.4 MB)

This bulletin summarizes recent climate data and presents it in a historical context. It first examines the national average temperature for the season and then highlights interesting regional temperature information.

Over the past decade, precipitation monitoring technology has evolved and Environment and Climate Change Canada (ECCC) and its partners implemented a transition from manual observations to using automatic precipitation gauges. Extensive data integration is required to link the current precipitation observations to the long term historical manual observations. The update and reporting of historical adjusted precipitation trends and variations will be on temporary hiatus pending the extensive data reconciliation, and will resume thereafter. ECCC remains committed to providing credible climate data to inform adaptation decision making, while ensuring the necessary data reconciliation occurs as monitoring technology evolves.

Temperature departures and rankings data table (CSV, 9 kB) 
Temperature trends and extremes data table (CSV, 2 kB)

National temperature

The national average temperature for the spring (March-May) of 2021 was 1.4°C above the baseline average (defined as the mean over the 1961–1990 reference period), which is the 14^th warmest observed since nationwide recording began in 1948 (based on preliminary data). The warmest spring occurred in 2010, when the national average temperature was 4.0°C above the baseline average. The coolest spring occurred in 1974, when the national average temperature was 2.0°C below the baseline average. The temperature departures map for the spring of 2021 (below) shows that most of Canada experienced temperatures at least 0.5°C above the baseline average except for the central region of Yukon and the eastern part of Northwest Territories that shown more than 1°C below the baseline average. Most notably, northern and eastern Nunavut experienced temperatures more than 3°C above the baseline average during the spring of 2021.

Temperature departures from the 1961 to 1990 average - Spring 2021

The time series graph (below) shows that averaged spring temperatures across the country have fluctuated from year to year over the 1948–2021 period. The linear trend indicates that spring temperatures averaged across the nation have warmed by 1.6°C over the past 74 years.

Spring national temperature departures and long-term trend, 1948-2021  

Regional temperature

When examined on a regional basis, average spring temperatures for 2021 were among the 10 warmest on record, since 1948, for three of the eleven climate regions. These regions were the Arctic Mountain and Fiords region (4^th warmest at 3.6°C above average), the Great Lakes/St. Lawrence region (7^th warmest at 1.9°C above average), and the Northeastern Forest region (9^th warmest at 2.2°C above average). Average spring temperatures for 2021 were not among the 10 coolest on record, since 1948, for any of the eleven climate regions. All eleven climate regions exhibit positive trends for spring temperatures over the 74 years of record. The strongest regional trend (+2.4°C) is observed in the Yukon/North B.C. Mountains region, while the weakest trend (+0.8°C) is found in the Atlantic Canada region. Tables listing the Spring regional and national temperature departures and rankings from 1948 to 2021 (CSV, 9kB) and summarizing the Spring regional and national trends and extremes (CSV, 2kB) are available through the above links or by request to ec.btvc-ctvb.ec@canada.ca.

Please note that the latest generation of CANGRD is now adopted in the analyses of the Climate Trends and Variations Bulletin (CTVB). For more information, please visit: About CTVB.

The map of Canadian Climate Regions