As a follow up to yesterdays post about monthly anomalies in Canada of +15C or higher and -15C and colder, I thought I would take a look what happens if I set the bar at +10C or -10C.
I am using Environment Canada Normals from their monthly summaries. The values are the anomaly from the 1971-2000 average (the Normals).
In 1936, 3.6% of the monthly anomalies were -10C or colder than normal.
A -10C or lower deviation from normal for a whole month is definitely extreme!
And notice 1982 is the most recent year to make the top 25.
Top 25 Cold Anomaly Months in a Year (by %)
| Year | Anomaly_Count | Cold_Anomalies | Hot_Anomalies | Pct_Cold_Anomalies | Pct_Hot_Anomalies |
| 1936 | 2281 | 82 | 0 | 3.595 | 0 |
| 1907 | 555 | 17 | 0 | 3.063 | 0 |
| 1899 | 433 | 13 | 0 | 3.002 | 0 |
| 1950 | 3868 | 116 | 0 | 2.999 | 0 |
| 1896 | 374 | 11 | 0 | 2.941 | 0 |
| 1916 | 1332 | 36 | 0 | 2.703 | 0 |
| 1890 | 277 | 7 | 0 | 2.527 | 0 |
| 1904 | 525 | 10 | 0 | 1.905 | 0 |
| 1937 | 2361 | 40 | 0 | 1.694 | 0 |
| 1969 | 9771 | 159 | 5 | 1.627 | 0.051 |
| 1917 | 1349 | 21 | 1 | 1.557 | 0.074 |
| 1893 | 327 | 5 | 0 | 1.529 | 0 |
| 1979 | 13984 | 196 | 4 | 1.402 | 0.029 |
| 1891 | 272 | 3 | 0 | 1.103 | 0 |
| 1897 | 373 | 4 | 0 | 1.072 | 0 |
| 1982 | 14928 | 154 | 0 | 1.032 | 0 |
| 1933 | 2172 | 20 | 0 | 0.921 | 0 |
| 1939 | 2658 | 20 | 1 | 0.752 | 0.038 |
| 1922 | 1557 | 11 | 0 | 0.706 | 0 |
| 1966 | 8479 | 58 | 0 | 0.684 | 0 |
| 1911 | 674 | 4 | 1 | 0.593 | 0.148 |
| 1951 | 4120 | 24 | 0 | 0.583 | 0 |
| 1955 | 4756 | 27 | 0 | 0.568 | 0 |
| 1954 | 4592 | 26 | 1 | 0.566 | 0.022 |
| 1930 | 2025 | 11 | 2 | 0.543 | 0.099 |
Hot Anomalies are much rarer.
Only .688% of the anomalies were 10C or higher in 2006. Thats less than 1/5th of the largest percentage of cold anomalies. It was also 6 years ago.
Top 25 Hot Anomaly Months in a Year (by %)
| Year | Anomaly_Count | Cold_Anomalies | Hot_Anomalies | Pct_Cold_Anomalies | Pct_Hot_Anomalies |
| 2006 | 6979 | 12 | 48 | 0.172 | 0.688 |
| 1931 | 2054 | 0 | 12 | 0 | 0.584 |
| 2001 | 9869 | 1 | 37 | 0.01 | 0.375 |
| 2010 | 5367 | 0 | 18 | 0 | 0.335 |
| 1981 | 14717 | 0 | 46 | 0 | 0.313 |
| 1926 | 1832 | 0 | 4 | 0 | 0.218 |
| 1947 | 3376 | 0 | 7 | 0 | 0.207 |
| 1977 | 13502 | 8 | 27 | 0.059 | 0.2 |
| 1943 | 3175 | 1 | 5 | 0.031 | 0.157 |
| 1911 | 674 | 4 | 1 | 0.593 | 0.148 |
| 1919 | 1403 | 2 | 2 | 0.143 | 0.143 |
| 1998 | 10503 | 0 | 15 | 0 | 0.143 |
| 1942 | 2977 | 1 | 4 | 0.034 | 0.134 |
| 1985 | 15582 | 84 | 20 | 0.539 | 0.128 |
| 2004 | 8159 | 0 | 9 | 0 | 0.11 |
| 2002 | 9206 | 42 | 10 | 0.456 | 0.109 |
| 1930 | 2025 | 11 | 2 | 0.543 | 0.099 |
| 1944 | 3280 | 1 | 3 | 0.03 | 0.091 |
| 1960 | 5870 | 0 | 5 | 0 | 0.085 |
| 2012 | 3750 | 2 | 3 | 0.053 | 0.08 |
| 2005 | 7581 | 0 | 6 | 0 | 0.079 |
| 1917 | 1349 | 21 | 1 | 1.557 | 0.074 |
| 1958 | 5466 | 0 | 4 | 0 | 0.073 |
| 1997 | 10891 | 2 | 8 | 0.018 | 0.073 |
| 1949 | 3693 | 11 | 2 | 0.298 | 0.054 |
sunshine hours 
That’s interesting stuff. When I say that 1968/69 was the coldest cold snap on record, I’m referring to BC, which is only once portion of the entire coutnry. If you take into account the three winter months (Dec, Jan, Feb), then the winter of 1968/1969 was by far the most below normal in British Columbia history.
I’m surprised not to see 1936 in the “hot” category since that was apparently the worst heat wave to hit Canada. Temperature reaching 44.4 degrees (112 F) in Manitoba. St Albans, Manitoba was over 40 degrees 9 days that summer. I believe this is a Canadian record for the most days reaching 40 or more degrees in a year.
“Glacier“,
even in July 1936, absolute anomalies in the northern Great Plains were considerably smaller than those in January and February 1931 or January 1926. The largest I found on the US climate division maps (‘http://gis.ncdc.noaa.gov/map/cag/#app=cdo’) was about 12.5˚F or 7˚C, whereas February 1931 had anomalies as high as +17.7˚F (+9.9˚C) in North Dakota and certainly had larger anomalies over western Canada. January 1931 was only marginally smaller, and in Alaska January 1926 was not exceeded for warmth until the record-breaking January 1981 when Fairbanks amazingly topped freezing on nearly half the days (next highest nine in the snow-drenched January 1937).