If you look specifically at January, our mean temp that month was in the mid to upper 20s for a large part of that decade with huge and historic arctic outbreaks in 1980, 1981, 1984, 1985 and 1989. But our Februarys were typically much warmer, so the cold was mostly confined to January (and sometimes December, as in 1989.)
Cold and dry followed by rainy cutters was a big thing back then and sometimes we had small to moderate snowfalls.
There were some underrated winters in the 80s though
Christmas 1980 the only time I've ever seen it get below 0 on Christmas and snow fell!
I find 1981-82 to be an extremely underrated winter-- check out what happened in January and then of course we had April.
1982-83 had the big HECS and the latest accumulating snowfall on record on April 20th.
1983-84 had the aforementioned moderate snowfalls (two 4 inchers) but was an extremely cold winter.
January 1985 had the largest arctic outbreak I've ever experienced.
January 1987 is an underrated winter storm.
1987-88 was an underrated winter.
December 1989 we already discussed-- it was as frigid as our coldest Januarys.
Keep in mind that although Central Park *only* got down to -1 or -2 in these arctic outbreaks (much colder than anything we've had since 2016 as it is), Newark and even Philly were MUCH colder. Around -10 on Christmas 1980, January 1982, January 1985.
Could you imagine the headlines if it got down to -10 in the metro area now?
real temperature-- not wind chill!