| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | -8.4° | -23.4° | — | — | 24 |
| February | -2.8° | -19.7° | 8.9mm | 10 | 10 |
| March | 4.4° | -9.6° | 17.2mm | 14 | 7 |
| April | 13.6° | -1.3° | 30.3mm | 10 | 55 |
| May | 20.8° | 4.6° | — | — | 94 |
| June | 25.3° | 11° | 92.7mm | 17 | 70 |
| July | 27.7° | 15.2° | 151mm | 16 | 67 |
| August | 26.9° | 13.9° | 67.3mm | 13 | 74 |
| September | 21.9° | 7.3° | — | — | 94 |
| October | 14.9° | -2.3° | — | — | 71 |
| November | 3° | -9.6° | — | — | 25 |
| December | -6.3° | -20.3° | — | — | 24 |
January in Hyesan averages a daily high of -8.4°C with nights around -23.4°C. A hard month to visit for comfort alone.
February in Hyesan averages a daily high of -2.8°C with nights around -19.7°C. Expect roughly 10 wet days totalling 8.9mm. A hard month to visit for comfort alone.
March in Hyesan averages a daily high of 4.4°C with nights around -9.6°C. Expect roughly 14 wet days totalling 17.2mm. A hard month to visit for comfort alone.
April in Hyesan averages a daily high of 13.6°C with nights around -1.3°C. Expect roughly 10 wet days totalling 30.3mm. Generally workable, with some weather to plan around.
May in Hyesan averages a daily high of 20.8°C with nights around 4.6°C. Comfortable conditions for being outdoors all day.
June in Hyesan averages a daily high of 25.3°C with nights around 11°C. Expect roughly 17 wet days totalling 92.7mm. Generally workable, with some weather to plan around.
July in Hyesan averages a daily high of 27.7°C with nights around 15.2°C. Expect roughly 16 wet days totalling 151mm. Generally workable, with some weather to plan around.
August in Hyesan averages a daily high of 26.9°C with nights around 13.9°C. Expect roughly 13 wet days totalling 67.3mm. Generally workable, with some weather to plan around.
September in Hyesan averages a daily high of 21.9°C with nights around 7.3°C. Comfortable conditions for being outdoors all day.
October in Hyesan averages a daily high of 14.9°C with nights around -2.3°C. Generally workable, with some weather to plan around.
November in Hyesan averages a daily high of 3°C with nights around -9.6°C. A hard month to visit for comfort alone.
December in Hyesan averages a daily high of -6.3°C with nights around -20.3°C. A hard month to visit for comfort alone.
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. Hyesan peaks at 94.
Based on 30 years of records, May scores highest for comfort in Hyesan, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 27.7°C.
July is the wettest, averaging 151mm of rain across roughly 16 wet days.
January is the coolest month, with average daily highs around -8.4°C.