Saturday, October 19, 2013

Fun With Statistics... Cooling Ahead

This is rather frivolous, but I couldn't resist another opportunity to illustrate the extreme climate of interior Alaska.  The chart below shows the range of possibilities for the amount of cooling that will be observed in Fairbanks over the next month, starting from yesterday's remarkable high temperature of 57 °F.  The probabilities are derived simply by looking at the lowest temperature observed by November 18 in each year back to 1930.  We are virtually assured of seeing temperatures below 0 °F in the next month, and it's not impossible that the temperature could drop nearly 100 °F, i.e. to -40°.  Only two years ago the temperature reached -41 °F on November 17.

By the way, the largest temperature drop observed in Fairbanks in 30 days or less is 100 °F, observed in both 1934 (34 to -66 °F in only 8 days) and 1935 (58 to -42).  The largest temperature rise in 30 days or less is 103 °F.


  1. January 2009 also feature extreme ranges, e.g. North Pole -55 on Jan 09 to +55 on Jan 16.

    1. Thanks for mentioning that one, Rick; that's a mind-blowing change for only one week. It appears Fairbanks warmed up 99 degrees in 8 days in that event.

      I searched the GHCN database for Alaska and found the largest 7-day temperature rise was at Eagle, from -67 to +50 between Feb 4 and 10, 1968... 117 F in 6 days! The largest 7-day drop was at Tok, +43 to -69 between Jan 22 and 27, 1962.

      The largest 30-day change (either direction) appears to be at Copper Valley School in Glenallen, +63 to -62 between Nov 19 and Dec 14, 1964. The data look slightly dubious on the cold end, though.