| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 30.1° | — | 5.5mm | 1 | 86 |
| February | 33.1° | — | 6.6mm | 0.9 | 74 |
| March | 35.7° | — | 19.3mm | 2.4 | 60 |
| April | 36.8° | — | 59.9mm | 5.9 | 49 |
| May | 35.2° | — | 172.2mm | 16 | 37 |
| June | 33.5° | — | 132.8mm | 18.1 | 44 |
| July | 32.4° | — | 151.2mm | 19.8 | 48 |
| August | 32.1° | — | 239mm | 23.1 | 50 |
| September | 32.4° | — | 284.7mm | 20.9 | 48 |
| October | 32.1° | — | 92.1mm | 7.6 | 64 |
| November | 31.7° | — | 64.6mm | 4.4 | 72 |
| December | 29.7° | — | 16.3mm | 0.8 | 88 |
January in Chiang Mai averages a daily high of 30.1°C. Rain is rare — about 1 wet days and 5.5mm across the month. Comfortable conditions for being outdoors all day.
February in Chiang Mai averages a daily high of 33.1°C. Rain is rare — about 0.9 wet days and 6.6mm across the month. Generally workable, with some weather to plan around.
March in Chiang Mai averages a daily high of 35.7°C. Rain is rare — about 2.4 wet days and 19.3mm across the month. Generally workable, with some weather to plan around.
April in Chiang Mai averages a daily high of 36.8°C. Expect roughly 5.9 wet days totalling 59.9mm. Demanding conditions — pack for it and plan indoor options.
May in Chiang Mai averages a daily high of 35.2°C. Expect roughly 16 wet days totalling 172.2mm. Demanding conditions — pack for it and plan indoor options.
June in Chiang Mai averages a daily high of 33.5°C. Expect roughly 18.1 wet days totalling 132.8mm. Demanding conditions — pack for it and plan indoor options.
July in Chiang Mai averages a daily high of 32.4°C. Expect roughly 19.8 wet days totalling 151.2mm. Demanding conditions — pack for it and plan indoor options.
August in Chiang Mai averages a daily high of 32.1°C. Expect roughly 23.1 wet days totalling 239mm. Demanding conditions — pack for it and plan indoor options.
September in Chiang Mai averages a daily high of 32.4°C. Expect roughly 20.9 wet days totalling 284.7mm. Demanding conditions — pack for it and plan indoor options.
October in Chiang Mai averages a daily high of 32.1°C. Expect roughly 7.6 wet days totalling 92.1mm. Generally workable, with some weather to plan around.
November in Chiang Mai averages a daily high of 31.7°C. Expect roughly 4.4 wet days totalling 64.6mm. Generally workable, with some weather to plan around.
December in Chiang Mai averages a daily high of 29.7°C. Rain is rare — about 0.8 wet days and 16.3mm across the month. Comfortable conditions for being outdoors all day.
Each month scores out of 100. It starts at 100 and loses points for daytime highs outside a 20–27°C band, for wet days, and for nights below 2°C. Nothing else is weighted in — no crowd data, no prices, no opinion. Chiang Mai peaks at 88.
Based on 30 years of records, December–January scores highest for comfort in Chiang Mai, balancing daytime temperature against rainfall.
April is the warmest, averaging a daily high of 36.8°C.
September is the wettest, averaging 284.7mm of rain across roughly 20.9 wet days.
December is the coolest month, with average daily highs around 29.7°C.