This is the information on their website:
January 1 - March 31: Wednesday through Sunday, 10 a.m.–4 p.m., closed Mondays and Tuesdays
April 1 - May 31: Tuesday through Sunday, 10 a.m.–5 p.m., closed Mondays except for Memorial Day
June 1 - October 31: Open daily, 10 a.m.–5 p.m; First friday of the month: 10 a.m. - 8 p.m.
July through September: Free Admission on Wednesdays 5 - 8 p.m
November 1 - December 31: Tuesday through Sunday, 10 a.m.–5 p.m., closed Mondays
The museum opens at 10 AM Tuesday through Sunday.
Probably best to go to their website. I THINK they are closed on Mondays but am not sure.
Get quick answers from Farnsworth Art Museum staff and past visitors.