October Warmth

Here are a few statistics that illustrate just how extremely unusual the recent warm spell has been across Alaska and northwestern Canada:

• Fort McPherson, in the far northwest of Canada's Northwest Territories, experienced its warmest October week of record for the 7 days ending yesterday (Oct 15-21), with an average temperature of 44.1 °F.  The old record, in a fairly complete period of record back to 1893, was 43.9 °F for Oct 1-7, 2003.  It is quite astonishing that this record could be broken in the second half of the month, considering the rapid pace of seasonal cooling at this time of year.
• In Anchorage, the week ending October 20 was the second warmest October week of record (weekly mean temperature of 49.0 °F, compared to 49.6 °F for Oct 1-7, 2003).
• McGrath saw its third warmest (non-overlapping) October week of record.  More remarkably, the Oct 13-19 average low temperature of 40.9 °F was the highest on record for any week either wholly or partially in October; the previous record was 40.7 °F for Sep 25 - Oct 1, 2002.  The chart below shows the recent history of daily minimum temperatures in McGrath.