Chiang Mai vs Ko Samui: which is better, month by month

Ko Samui beats Chiang Mai in 8 of 12 months — its lead peaks in August (82 vs 46) — while Chiang Mai wins November to December; they are within 3 points in January and October.

Each place is scored under the lens that suits its type — they are different kinds of destination, so the scores are each place at its own best. Comfort is SeasonMap's 0–100 estimate from ERA5 climate normals, not a forecast.

Chiang Mai

🇹🇭 Thailand · tropical climate

Best month: January 87/100
Months won: 2 of 12

Ko Samui

🇹🇭 Thailand · tropical climate

Best month: March 90/100
Months won: 8 of 12

Chiang Mai vs Ko Samui — all 12 months

Month	Chiang Mai	Ko Samui	Winner	Gap
January	87Ahot, dry	84Ahot, rainy, muggy air	Tie	3
February	82Asweltering, dry	88Asweltering, a little rain, muggy air	Ko Samui	6
March	65Csweltering, dry	90Ssweltering, a little rain, muggy air	Ko Samui	25
April	54Dsweltering, dry	80Asweltering, rainy, clean air	Ko Samui	26
May	52Dsweltering, rainy	77Bsweltering, rainy, clean air	Ko Samui	25
June	60Csweltering, rainy, clean air	83Asweltering, a little rain, clean air	Ko Samui	23
July	53Dsweltering, soaked, clean air	78Bsweltering, rainy, clean air	Ko Samui	25
August	46Fsweltering, soaked, clean air	82Asweltering, a little rain, clean air	Ko Samui	36
September	49Fsweltering, soaked, muggy air	73Bsweltering, rainy, clean air	Ko Samui	24
October	61Csweltering, soaked, muggy air	62Csweltering, soaked, clean air	Tie	1
November	74Bsweltering, a little rain, muggy air	59Dsweltering, soaked, clean air	Chiang Mai	15
December	84Ahot, dry	70Bhot, soaked, muggy air	Chiang Mai	14

A month is a tie when the two are within 3 points. The widest gap is August (46 vs 82). Tap a month for that month's temperature, rain, humidity and air quality side by side.