From a brief check at archived DCA temps, it's been very rare since 2016 to see significant snow and extended sub-freezing temps:
1/13/19 (10in) - temps above freezing rest of week
1/6/25 (7in) - temps above freezing rest of week
1/3/22 (7in) - one day of below freezing temps
2/1/21 (5in) - temps above freezing rest of week
Compared to this event where we haven't breached freezing since the event and are not forecast to till next week, at least a full seven days.