Day trip from Venice to the Dolomites

You will need to pay close attention to the weather that time of the year. Spring can be variable in weather and sometimes it is very rainy throughout the region. I prefer traveling through mountains a little later as snow may or may not still be a driving issue. And it would be nice if you had another day to spend in the Dolomites. There are also a number of other towns to visit other the Cortina.

A little early in the year for hiking isn't it? Likely to be pretty cool, with snow still on the ground

The Cortina area ski report says they currently have 3-5 feet of snow on the slopes and plan to stay open for skiing until May 1. While some areas may offer winter hiking trails or snowshoe trails, you should confirm that before committing to the daytrip.

Thanks for these thoughts and cautions. If the snow is deep, we will plan our exercise in town. Any suggestions for routes to take in the Dolomites? Take SR48 toward Monte Cristallo and stop for the views??

We took an organized Viator mini bus trip from Venice to the Dolomites mid- May in 2015.
We didn't see the mountain peaks at all due to the mist; and there was still a tiny bit of snow in Cortina.
We saw only lower areas all the way there and back.
It was also bitter cold!
We wore every piece of clothing we had with us!
Also: everything in Cortina closed at lunchtime.
We had just gone into a lovely shop selling great clothing, and were bundled out swiftly due to closing for lunch!
Maybe rethink your plan to go there in March!
Lots to do in Venice itself.

Ok.

March is springtime. We are expecting some wet weather.

Thanks for the reminder.

Cortina d'Ampezzo is wonderful. We stayed there a couple of nights, but I'd check the weather first.