First Philly freezes

Frost already has coated the car roofs and lawns outside the city, and Emily Dickinson's poetic "blonde assassin" has clipped the late-surviving flowers, but as we all know Philadelphia's official measuring station tends to be a warmer place.

The official temperature finally got to the freezing mark late last night at the airport, and this morning it made its first visit to the 20s since March 24, hitting 29 before daybreak.

Having a first official freeze in Philadelphia on Nov. 12 is on the late side given the period of record, dating to 1874, but very much in keeping with recent trends.

During the last decade, the first freeze has occurred around Nov. 13, on average.

The long-term average for the 140 years of records would be about Nov. 8, but the freeze dates have exhibited significant decadal varability.

In the 1960s, the average date was Oct. 22, the freezing reading of Oct. 5, 1961, holds the record for the earliest.

By contrast; in the 1930s, the average date was Nov. 20.

We don't know what this all means the coming winter, but the most-recent outlooks are favoring a cooler-than-normal  November.