Watertown Trick-or-Treat happens in residential neighborhoods from approx. 5-9PM.

Indoors from 4-7pm at the Watertown Mall on 550 Arsenal St; includes Costume Contest at 4pm with three winners in each of the 3 categories of (1) Infant-2yrs (2) 3yrs-5yrs and (3) 6yrs-12yrs. Vote for your favorite scarecrow; 28th Annual Scarecrow Contest, on display from Oct 18-Oct 31.

It’s also the 2nd Annual “Halloween by Hatch Costume Contest” at the Plumbing Museum, starting at 6:30PM, located at 80 Rosedale Road. Fun for all ages and free treats for all! Great local prizes awarded to the most creative youth and adult costumes. Come dressed in your best Halloween finery! Walk the runway and vote for your favorite. To participate, arrive between 6:30-7 PM to sign up; at least 50% of your costume must be handmade. Win great local prizes!