this is taking me back to late elementary school days but I remember some sort of coastal storm in March '94 where at least western areas got a lot of snow (we got around 20" in the Shen Valley).
Looks like DCA hit 36 (hit 38 at my station downtown) - DCA hasn't had a subfreezing high since the 2018-2019 winter. Hell we barely had 30s for highs last "winter".
i got caught in thundersleet once on a jog in NYC - it was NOT fun. i remember running by another runner - we were the only people out - and we both looked at each other like, "something is deeply wrong with us lol"
i'd imagine right there, but the most intense UHI in the entire city is actually Columbia Heights/Petworth area, so just a few blocks east from you really.