Hot and humid with the rainy season underway; temperatures stay in the high 20s to mid-30s °C and rainfall increases sharply from May onward. ([tmd.go.th](https://tmd.go.th/media/climate/climate-monthly/may-2026.pdf?utm_source=openai))
Ideal for: Cafes, cooking classes, spas, museums, and flexible itineraries with indoor backups. ([budgetyourtrip.com](https://www.budgetyourtrip.com/thailand/chiang-mai?utm_source=openai))
Pack: Breathable clothes, compact umbrella, rain jacket, quick-dry shoes, and waterproof bag cover. ([tmd.go.th](https://tmd.go.th/media/climate/climate-monthly/may-2026.pdf?utm_source=openai))