For anyone who was looking to debate the issue, it's now official that 2012 was the hottest year on record for the contiguous United States. For Canada, there's still room for discussion until our official numbers come out, but so far, it's not looking good.
The U.S. National Oceanic and Atmospheric Administration (NOAA) and the National Climatic Data Center (NCDC) released their 2012 State of the Climate report today, stating that the annual average temperature for the contiguous United States was 55.3 degrees Fahrenheit (12.9 degrees Celsius), which was 3.2°F (1.8°C) above the twentieth-century average and beat out the previous record high, from 1998, by 1°F (0.6°C).
According to Environment Canada's Climate Trends and Variations Bulletins, Canada's temperatures were above the national average (1961-1990) for each season from Winter 2011/2012 through to Autumn 2012.
Although there were regional differences, last winter's national average temperature ranked third hottest of all winters since 1948 at 3.6°C above average, lagging behind 2006 (+3.9°C) and 2010 (+4.1°C). Last spring ranked a cool 9th nationwide, at 1.6°C above average (2010 the hottest still at +4.1°C), but summer made up for it by rocketing to the top of the chart with 1.9°C above average, beating out the 1998 record by two-tenths of a degree. Autumn favoured us with cooler days, overall, but even though the season only ranked as 17th hottest, it was still 1.2°C above average.
All these above-average temperatures may not look impressive, however 2011 still ranked as the 8th warmest year on record, even though the rankings of its individual seasons weren't that impressive — winter 7th, spring 37th, summer 3rd, autumn 3rd.
Last year may not take the top spot, overall (that's still 2010), but with summer taking the top position and the winter ranking 3rd, the year stands a good chance of at least making the top 5, and it may even give 1998 (currently in 3rd) and 2006 (currently in 2nd) a good run for their money.