January, with the arrival of the much-ballyhooed polar vortex, ranked as the 17th coldest on record, dating to 1895. Temperatures across the state bottomed out at –13 degrees. On January 7 at High Point, the wind chill measured –27 degrees.
But for all the cold, it was also a month of temperature swings. While 12 days dropped to 0 degrees or lower, 11 days reached 50 degrees or higher. Five days reached 60 degrees or higher, including a 64 degree day in Cherry Hill.
It was also a snowy January, the 8th snowiest on record. Six different snowfalls of two inches or more occurred in the state:
http://climate.rutgers.edu/stateclim/?section=menu&target=jan14
The phrase “polar vortex” is now a contender for word (or, in this case, phrase) of the year. Scientists still don’t know exactly what role global warming might have played in the extreme cold that visited New Jersey in January (it seems counter-intuitive, right?) but many climatologists believe they are linked. Jennifer Francis, a researcher at Rutgers, is one of the leading figures in the scientific community doing research that suggests the cold weather is related to instability in the jet stream. The warmer air didn't disappear, it merely got rerouted to Alaska:
http://news.rutgers.edu/hot-topic/global-warming-behind-polar-vortex/20140129#.UvEUa93Pa4B
According to this article in the Anchorage Daily News, the plants in Alaska are very confused:
http://www.adn.com/2014/01/28/3296179/record-warmth-and-confused-plants.html