I looked up less then 32 degrees consecutive days at BWI for a few years I was curious about (therefore, I have no idea if 1989 is the record, these are only the ones I checked).
1/16/77 - 1/23/77: 8 days
2/9/79 - 2/15/79: 7 days
12/16/89 - 12/25/89: 10 days
1/19/94 - 1/21/94: 3 days (this one really shocked me! Time goes slower when you're a kid)
2/15/15 - 2/20/15: 6 days
12/31/17- 1/7/18: 8 days
Current streak (as of yesterday): 9 days.
This is out-of-scope to the time period discussed, but I had to check this one too: 2/8/1899 - 2/15/1899 was 8 days.