Best time for Switzerland AND an Amalfi Coast trip?

I was in Murren last July (mid-July in fact) and never once would I call it "hot." Or any part of Switzerland hot. In fact at night I would call Murren "freezing." Like "this lightweight windbreaker I brought is definitely not cutting it." Ha! I know "hot" is relative, but to my Georgia self, it was "warm" during the day, not very humid, definitely not what I would consider hot like Florida. Now, Rome and Cannes, on the other hand, in mid-July was HOT.

It can get warm and humid in the low-altitude areas of Switzerland, such as the cities of Zurich, Luzern, Bern and Basel. But in the mountains, the altitude keeps it cool.

We were in Switzerland for two weeks last July-August, during the major heat wave that swept across most of Europe. The cities we passed through on our way (Amsterdam and Basel) were indeed quite hot, but in the mountain villages (Muerren and Bettmeralp) it was very pleasant, and even cool at night.

We have been to Switzerland five times, usually in July or August, and have never found heat to be an issue. The one time we went in June (end of June) the weather was cool and unsettled much of the time. We even had a blizzard on July 1 in Zermatt.

Thanks for the replies. I'm gathering that June in Switzerland can still be a "transitional" weather month. Glad I have a year to plan.

I took an RS 2-week tour through the Alps in early June. From the "tour reviews" that year, the one before mine (late May) and after ( late June) had excellent weather. My tour was plagued with poor weather. 2 nights in Lauterbrunnen and never saw an alp because of the heavy cloud cover. Even the long drives were not that great because of the low clouds through Switzerland. And I got soaked because of prolonged heavy rain in the Italian Dolomites and Salzburg too. In other words, it's Europe, it's late spring, it's mountains, in short it's unpredictable.

Thanks, Chani, seems this year is also a weather-challenged spring in Europe. Sorry about your trip. Maybe next time will be better.

We were in the Amalfi Coast from May 12-20, 2017 and in Switzerland June 18-28, 2018 and we had great weather on both trips. It was sunny and in the 70's. On the Amalfi Coast we stayed in Positano and took the boat to Amalfi and the City Sightseeing bus from Amalfi to Ravello on a day trip. We also stayed in Sorrento and took the boat to Capri and the train to Pompeii. I wore shorts or capris and short sleeved tops. It was lovely weather.
Switzerland was great weather for us in June. In Lausanne, Interlaken, Luzern, and Zurich it was warm and sunny. In Wengen and Lauterbrunnen in the mountains it was cooler and sometimes foggy, so there I wore a light jacket.
Both areas are beautiful and I hope you have fun planning your trip.