Should travellers avoid Chiang Mai during burning season?
When smoke is bad, the north can become a very different trip. Check current air quality close to travel and be willing to move time south, rather than forcing Chiang Mai because it looked perfect months ago.
Answer
Burning season is not a minor aesthetic issue when air quality is poor. It can affect views, comfort, outdoor plans and how much you enjoy walking, eating outside or travelling with children. The answer is not to write off northern Thailand forever; it is to stop treating it as season-proof. If Chiang Mai is central to the trip, build flexibility into the route and watch current conditions as dates approach. If you are sensitive to smoke, travelling with young children, or only have a short holiday with no room to pivot, choose a different season or shift more time to Bangkok and the islands. The payoff is real when conditions are good; so is the friction when they are not.