DAy trip to plymouth from Boston

If your purpose is whale-watching, take a boat from Boston Harbor. They all go to the same place, Stellwagen Banks, to see the same whales. Spend your time on the water rather than on the highway.

The commuter rail runs from downtown Boston to Plymouth a few times a day... it's do-able, although you would have to plan the times carefully. See: commuter rail schedule for more info. That said, if you are heading down to Plymouth only for the whale watch, keep in mind that several whale watch boats run from Boston itself. The larger issue is when you're coming -- most whale watches, I believe, don't start until early April.

In mid-March, the weather will be very variable in Boston -- it could still be really cold (down to 0 degrees celsius at night, or possibly, still during the day) or much warmer. We had a mild couple of months, but now it's mid-Feb and winter is still here for a while. Your best bet would be to check the weather as close to when you leave as you feel comfortable with. Definitely bring a jacket, some sweaters, and very possibly gloves. If I had to guess, I'd say 7-8 degrees during the day, and closer to 0 at night.

Welcome to Boston!

As above, all the whale watches in MA go to the same place, to see the same whales. The Boston-based ones leave from the New England Aquarium. Their whale watch cruises don't begin until April, as #2 says. You could still go to Plymouth to see the historic stuff, but since you're from the UK, it might be kind of old hat (!) to you.

It's Plimoth Plantation. I think that for a UK native, the experience would be less than thrilling.

ola can check out the link, though - I could be wrong.

All good advice, but check weather.com or weather underground for averages and such. It can be pretty cold mid march. In fact I'd say the odds are good it will be. I liked the place, but a lot of the things to see and do are outdoors. Keep that in mind.

Ed