| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 28.7° | 13.9° | 11.5mm | 0.9 | 91 |
| February | 31.3° | 14.7° | 20.1mm | 2 | 79 |
| March | 33.6° | 17.7° | 43.2mm | 4.4 | 65 |
| April | 34.4° | 21.1° | 91.9mm | 9.7 | 51 |
| May | 33.2° | 22.9° | 229.3mm | 19.1 | 45 |
| June | 32.5° | 23.9° | 209.2mm | 21.1 | 48 |
| July | 31.3° | 23.8° | 324.2mm | 23.3 | 53 |
| August | 31° | 23.6° | 381.6mm | 24.9 | 54 |
| September | 31.4° | 22.9° | 287.2mm | 19.9 | 52 |
| October | 31.1° | 21.6° | 75.9mm | 7.8 | 68 |
| November | 29.7° | 18.2° | 61.1mm | 5.3 | 79 |
| December | 28° | 14.3° | 9.9mm | 1.7 | 93 |
January in Chiang Rai averages a daily high of 28.7°C with nights around 13.9°C. Rain is rare — about 0.9 wet days and 11.5mm across the month. Comfortable conditions for being outdoors all day.
February in Chiang Rai averages a daily high of 31.3°C with nights around 14.7°C. Rain is rare — about 2 wet days and 20.1mm across the month. Comfortable conditions for being outdoors all day.
March in Chiang Rai averages a daily high of 33.6°C with nights around 17.7°C. Expect roughly 4.4 wet days totalling 43.2mm. Generally workable, with some weather to plan around.
April in Chiang Rai averages a daily high of 34.4°C with nights around 21.1°C. Expect roughly 9.7 wet days totalling 91.9mm. Demanding conditions — pack for it and plan indoor options.
May in Chiang Rai averages a daily high of 33.2°C with nights around 22.9°C. Expect roughly 19.1 wet days totalling 229.3mm. Demanding conditions — pack for it and plan indoor options.
June in Chiang Rai averages a daily high of 32.5°C with nights around 23.9°C. Expect roughly 21.1 wet days totalling 209.2mm. Demanding conditions — pack for it and plan indoor options.
July in Chiang Rai averages a daily high of 31.3°C with nights around 23.8°C. Expect roughly 23.3 wet days totalling 324.2mm. Demanding conditions — pack for it and plan indoor options.
August in Chiang Rai averages a daily high of 31°C with nights around 23.6°C. Expect roughly 24.9 wet days totalling 381.6mm. Demanding conditions — pack for it and plan indoor options.
September in Chiang Rai averages a daily high of 31.4°C with nights around 22.9°C. Expect roughly 19.9 wet days totalling 287.2mm. Demanding conditions — pack for it and plan indoor options.
October in Chiang Rai averages a daily high of 31.1°C with nights around 21.6°C. Expect roughly 7.8 wet days totalling 75.9mm. Generally workable, with some weather to plan around.
November in Chiang Rai averages a daily high of 29.7°C with nights around 18.2°C. Expect roughly 5.3 wet days totalling 61.1mm. Comfortable conditions for being outdoors all day.
December in Chiang Rai averages a daily high of 28°C with nights around 14.3°C. Rain is rare — about 1.7 wet days and 9.9mm 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 Rai peaks at 93.
Based on 30 years of records, December–January scores highest for comfort in Chiang Rai, balancing daytime temperature against rainfall.
April is the warmest, averaging a daily high of 34.4°C.
August is the wettest, averaging 381.6mm of rain across roughly 24.9 wet days.
December is the coolest month, with average daily highs around 28°C.