London in May: what the weather really brings

May in London sits in that sweet spot where winter's grip has fully released but summer heat hasn't arrived. Daytime highs average 17.9°C (64°F), while mornings dip to 8.8°C (48°F)—crisp enough that you'll want a layer, but nothing requiring a winter coat. You'll get roughly 10.8 hours of sunshine daily, though rain falls on about 11 days of the month, totaling 53mm. The rain tends to come in quick showers rather than all-day downpours; locals joke that May's unpredictability is part of its charm. Evenings cool noticeably, especially along the Thames, where a breeze picks up after sunset.

The city feels alive in May without the wall-to-wall crowds of June and July. Royal parks burst with cherry blossoms and bluebells—St. James's Park and Kew Gardens are at their peak. Chelsea Flower Show happens mid-May, drawing horticulture enthusiasts but also clogging west London with temporary traffic. Prices for accommodation and flights are still reasonable compared to summer, though they've ticked up from April. Locals emerge from their homes; outdoor pub seating fills up on sunny afternoons, and the South Bank hums with street performers and tourists in a ratio that still feels manageable.

May 2026 will likely track with the historical pattern—the month has remained relatively consistent over the past decade, with temperatures holding steady around 18°C and rainfall predictable. Climate data suggests no dramatic shifts for this year, so pack for variability rather than extremes. The 11 rainy days forecast is slightly above the ten-year average, so waterproofing isn't optional.

This month rewards photographers (long daylight, soft spring light), families (school holidays haven't started, so fewer queues at attractions), and anyone who wants to explore on foot without melting. In 2026, book outdoor walking tours, visits to the British Museum, and riverside picnics around the weather forecast, but don't cancel plans for rain—a light jacket and an umbrella will see you through. If you're sensitive to cold, layer up; if you love mild weather and gardens in bloom, May is your month.