Best way to take a day trip from Lake Como to Switzerland in February?

Before anyone can answer, we need to know where on Lake Como you will be staying. There are several possibilities for a Swiss visit, but the appropriate solution depends on where you are starting.

Yes to what Lola says. Where you can conveniently get to on a day trip depends on where on Lake Come you are staying.

"Can you take a ferry in February and ride a train?" - yes of course you can. Do you think Swiss transport shuts down in winter? People need it to get around.
All rail lines and all 1838 stations in Switzerland have at least one train per hour, 18 hours a day 365 days a year.

• There is a rail line along the east side of Lake Como, From Milan to Tirano If you are staying there (e.g. Varenna), you can take a day trip on the Bernina Pass routeover the Alps to Chur and back.
• Como town (not the best place to stay) is on the main rail line from Milan north into Switzerland. Trains to Lugano. Worth a visit.
• Menaggio on the west side of the lake has local buses to Lugano.
• Other points on the lake need a bus or ferry to reach a rail line.

I failed to mention that we're staying in Varenna.

OK, from Varenna you just take the train north to Tirano on the Swiss border. Trains depart Varenna in the morning at 7:24 and 8:24 and take 1.5 hours to reach Tirano. There you walk the short distance to the Swiss station and board the regional Swiss train on the Bernina Pass route (you do not need to take the Las Ed Bernina Express train). I suggest you ride over the pass and get off in the town of Pontresina, a ski resort. This will be another two hours on the train and it is very scenic.

In Pontresina you will find shops and restaurants for lunch. There are lifts that you may be able to ride up and back down. spend a few hours there and then return to Varenna the way you came. There is also a bus route via Colico if you would rather make a loop trip than two train rides on the same tracks. But the Bernina Pass is so scenic, especially dropping down from the pass to Poschiavo, that I recommend taking the train both ways.

This sounds like an amazing day trip. I'm excited to have this information to start our planning! Thank you!

We stayed in Pontresina for several days. The houses are painted with decorations, motifs, a very charming place to visit. It is a much nicer town to stay than St-amortize which is nearby.