Very Big Chill: The month that froze Philly
January 1977 remains unmatched for cold in local records.
On this date 40 years ago, the temperature didn't get above freezing – and that ended up being the second-warmest day of the month.
January 1977 went on to become the coldest month in Philadelphia's period of record, dating to 1874.
All 31 days finished with below-normal temperatures, climaxing on the 17th, when the high was 8 and the low got down to 4 below zero. The average temperature was 31 degrees below the normal for the date.
Cold was widespread across the county, straining energy supplies and locking ships in ice.
The monthly average temperature for January 1977 in Philadelphia, 20, set a standard for any month in the period of recordkeeping.
One thing it had all over January 2017, however, was sunshine. In all, January 1977 produced 10 "clear" days – Arctic air masses aren't all bad.
So far, this month has given us a grand total of one clear day.