Rainy-season Chiang Mai is less disrupted by showers when you split the day into temples in the morning, indoors in the afternoon and a show in the evening. Art in Paradise and Fahlanna Art Museum take the daytime indoors and the Siam Dragon Show starts at 20:00 to close the day seated.
With parents, look at sitting time rather than distance walked. Fahlanna Art Museum has storage for bags and umbrellas and a cafe, and the Siam Dragon Show is about 70 minutes in a seat. Old Town costumes require arrival 30 minutes before your time, so leave slack before a temple visit.
With children, height bands shape the plan. Children are 101 to 140 cm at Art in Paradise, 101 to 139 cm at Night Safari and 111 to 159 cm at Tiger Kingdom. Pregnant guests and the elderly will find Tiger Kingdom difficult, so choose to suit your party.
Even in the wetter months Grand Canyon Water Park and Tiger Kingdom go ahead in light rain. Choosing not to attend gives no full refund, though, so move the plan on a day with a clearly bad forecast. Night Safari takes same-day bookings only until 11:00.
The Muay Thai class sits in the middle of the Old City and runs from 08:30 to 20:00, so it slots easily into a rainy morning or an evening. Bring shorts and training wear, and prepare your own shower items.