Jackets in Varrena in early May?

In Varenna you aren't likely to need heavy jackets. Varenna is not in the Dolomites, it's on Lake Como (650 ft above sea level), which is not much higher in altitude than the city of Milan, where it will be rather warm. In May temperatures in Varenna should be in the low 20s centigrade (low 70s F) during the day, and about 10-15 C (50s F) at night.

If you indeed go to the Dolomites, especially at high altitude, yes you will need jackets, and when the sun is down, you will likely need heavy jackets. It does snow in May sometimes on top of those mountains.

Roberto, the itinerary for the Best of Italy in 17 days tour starts in Varenna for 2 nights then goes to the Dolomites for 2 nights. I think the tour often stays at Castelrotto with a free day in the area to explore whatever can be explored, lol.

I have NOT been on this tour yet...it's coming up for me at the end of Sept/early October.

I do not know where you are from so it's hard to gauge your possible tolerance to cold weather. If I were going then (and I am pretty cold tolerant), I'd plan on a waterproof jacket with a hood and have a puffy vest underneath it for colder weather. I'd probably take glove liners as well...the ones I routinely have here at home are Smartwool but they are expensive and if you don't live in an area where you are likely to use them, I'd go with a less expensive option. I am pretty cold tolerant and it's only one day so I could manage even if it got really chilly. For the rest of the tour you are not going to need this level of warmth!

The puffy vest I like is the 32 Degree brand from Costco. They are under $20 and keep me warm with this combo all winter unless it's very windy and below about 25.

I always travel to Europe with a waterproof outer layer, no matter what the season!