Chiang Mai has a tropical climate, but is cooler and less humid than most of Thailand. The city experiences monsoons: the southwest monsoon arrives from India at the end of May and lasts until November, with the heaviest downpours in August and September. Rain usually occurs in the late afternoon. Summer temperatures range from 73°F (23°C) to 98°F (37°C). Between November and May cool air blows in from China and northern Vietnam, bringing a dry season with mild days and balmy nights. Temperatures are at their lowest in December and January, dropping to about 59°F (15°C), and it is chilly enough to require a warm jacket at night, although temperatures can still reach 86°F (30°C) during the day.
