By Rick Steves
July and August are peak season throughout England, Scotland, and Wales — with very long days, the best weather, and the busiest schedule of tourist fun. May and June can be lovely anywhere in Britain.
Except during holidays and festivals, prices and crowds don't go up during peak times as dramatically in England and Wales as they do in much of Europe. But while Scotland never quite feels "crowded," in some areas its finite number of B&Bs and restaurants are jam-packed in July and August (with Edinburgh being especially swamped throughout August, its festival season). London's biggest summer events, however (including Wimbledon in July, and the Notting Hill Carnival in late August) don't overwhelm the city.
Across Britain, travel during "shoulder season" (May, early June, September, and early October) is still easier than in peak season, and can be a bit less expensive. Shoulder-season travelers usually enjoy smaller crowds, better room availability (and prices), and the full range of sights and tourist fun spots, including London's Chelsea Flower Show in May and the Trooping of the Colour pageantry in June. Even in the peak of summer, however, sunny weather is far from guaranteed (especially in Scotland's damp and chilly climate) — you may do just as well in shoulder season. And various Highland Games are held across Scotland as early as May, and as late as September.
Winter travelers encounter few crowds and soft room prices (except in London), but sightseeing hours are shorter and the weather is reliably bad. In the countryside, some attractions are open only on weekends or close entirely in the winter (November–February). The weather can be cold and dreary, and nightfall draws the shades on sightseeing well before dinnertime. While rural charm falls with the leaves, city sightseeing is fine in the winter. Christmastime is especially fun in London, while Edinburgh is the place to be for Hogmanay (New Year's Eve).
Plan for rain no matter when you go. If (when) it happens, just keep traveling and take full advantage of bright spells. The weather can change several times in a day, but rarely is it extreme. As the locals say, "There is no bad weather, only inappropriate clothing." Bring a jacket and dress in layers. Temperatures below 32°F cause headlines, and days that break 80°F — while more frequent in recent years — are still rare in Britain. While sunshine may be fleeting, summer days are very long. The midsummer sun is up from 6:30 until 22:30. It's not uncommon to have a gray day, eat dinner, and enjoy hours of sunshine afterward.