First Frost is Due
The average date of the first fall frost ranges from mid-September to late November.
The average date of the first fall frost (low temperature less than or equal to 32°F) ranges from mid-September in higher elevations of northern New England and northern New York to mid- to late November for locations closer to the coast such as Washington, D.C., and New York City. For more than half of the 35 major climate sites, that average date falls some time in October.
Average, earliest, and latest date of the first fall frost at the major climate sites.
The Northeast has been experiencing unusually mild temperatures since September, with the first half of October being record or near-record warm for many locations. As of October 20, none of the 35 major climate sites have dropped to 32°F, with the first fall frost running late at 17 of the sites. In fact, when Caribou, ME, sees its first frost of the season, it’ll be the latest on record, surpassing the old record of October 17.
Of the major climate sites, LaGuardia Airport, NY, holds the record for latest frost, not seeing their first frost of 2015 until January 4, 2016. On the other end of the spectrum, the earliest fall frosts have actually arrived during summer. Concord, NH, holds the honor of the major climate site having the earliest fall frost, August 29 (in 1986, 1965, and 1976).
Average, latest, and this year’s date (and rank) of fall’s first low temperature less than 50°F at some major climate sites.
Another fall milestone for some southern locations and cities along the Interstate 95 corridor is the first low temperature below 50°F. The average date at these sites ranges from mid-September to early October. This fall, the first sub-50°F low temperature was up to 4 weeks later than usual at some sites, with low temperatures at LaGuardia Airport yet to fall below 50°F as of October 20. In fact, this fall’s first low temperature below 50°F was the latest on record at five major climate sites - Providence, RI; Bridgeport, CT; Boston, MA; Newark, NJ; and Kennedy Airport, NY. NOAA’s Climate Prediction Center indicates milder-than-usual temperatures could stick around through the remainder of October.
Above-normal temperatures are favored through the rest of October. Click to enlarge.