At least the coating of frozen rain was pretty thin. I'm sure it will all melt out quickly. Boston does get snow in April every three or four years. But it isn't something that I expect.
I'm sure my little bunching onion seedlings didn't expect it either. Poor things. Luckily everything I have planted now can handle it. Even the onions seedlings above will be just fine even if they are mad at me for not taking them in last night.