Italy: Feast of San Nicola in Bari, the Feast of San Gennaro in Naples, the Festival of Snakes in Abruzzo.
Chaumont Garden Festival – thirty wonderful and sometimes wacky show gardens around a perfect chateau (castle), every year 15 May-19 October.
England: Isle of Man TT (motorcycle) Races, May/June.
London, Chelsea Flower Show – 11 acres of the UK’s (and arguably Europe’s) best flowers and gardens event, with plenty of original, even wacky ideas.
Glyndbourne Festival Opera (in a Stately Home outside London), late May-early July.
Netherlands: Tulip season.
Austria: Vienna International Festival from mid-May to mid-June; a wide range of arts, especially music, naturally, but also dance and theatre, sometimes challenging pieces, all set in magnificent buildings.
Meanwhile the magical Moorish cities of Seville, Cordoba and Granada, are beginning to overheat so this is the last bearable month before the summer. The Andalusian cities of Malaga and Cadiz offer decent beaches and fair amount of Spanish culture so they will be worth a visit.
Barcelona is a lively, fascinating city, spiced up by weird Gaudi architecture and perfect now.
All of the UK is in business now: England – nearly not Europe now! – should be looking and feeling good now. London always makes a great visit even if accommodation is pricey, the superb free museums and galleries make up for it. Stonehenge is not far, nor is Canterbury, Oxford or Cambridge. Down south English Beaches are beginning to buzz.
France: May is the best time to visit Paris‘ fantastic attractions, as well as the Loire Valley, Carcassonne, the Dordogne, Avignon, Arles and Aix-en-Provence and masses more medieval French cities. Biarritz and other Atlantic beach resorts roll into action now.
The Côte d’Azur will start to get very warm in May with plenty of sunshine, though ironically it always seems to rain sometime during Cannes Film Festival. Visit Cannes, Nice, Antibes, Menton, Monaco, St. Tropez along with the delightful little villages such as Eze, St Paul de Vence, all attractive, interesting and still not too busy in May.