yep that's what happens. first freeze (at least since i've moved back to DC) seems to be that 2nd/3rd week of Nov (looks like that'll be the case this year as well). But then below freezing temps are still pretty infrequent until after Christmas, so they come back.
Urban areas of the metro really only have like 6-8 weeks where temps reliably get below freezing, which is kind of insane. By late Feb/March the mosquitos are back lol.