| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 9.1° | -2.3° | — | — | 53 |
| February | 12° | — | — | — | 68 |
| March | 18.3° | 6° | — | — | 89 |
| April | 24.8° | 12.1° | — | — | 94 |
| May | 31.5° | 16.7° | — | — | 76 |
| June | 36.8° | 20.6° | — | — | 55 |
| July | 38.4° | 21.8° | — | — | 48 |
| August | 36.6° | 19.5° | — | — | 56 |
| September | 31.6° | 14.6° | — | — | 76 |
| October | 24.4° | 9.8° | — | — | 94 |
| November | 16.3° | 4.5° | — | — | 82 |
| December | 10.4° | -1.2° | — | — | 58 |
January in Koson averages a daily high of 9.1°C with nights around -2.3°C. Demanding conditions — pack for it and plan indoor options.
February in Koson averages a daily high of 12°C. Generally workable, with some weather to plan around.
March in Koson averages a daily high of 18.3°C with nights around 6°C. Comfortable conditions for being outdoors all day.
April in Koson averages a daily high of 24.8°C with nights around 12.1°C. Comfortable conditions for being outdoors all day.
May in Koson averages a daily high of 31.5°C with nights around 16.7°C. Comfortable conditions for being outdoors all day.
June in Koson averages a daily high of 36.8°C with nights around 20.6°C. Generally workable, with some weather to plan around.
July in Koson averages a daily high of 38.4°C with nights around 21.8°C. Demanding conditions — pack for it and plan indoor options.
August in Koson averages a daily high of 36.6°C with nights around 19.5°C. Generally workable, with some weather to plan around.
September in Koson averages a daily high of 31.6°C with nights around 14.6°C. Comfortable conditions for being outdoors all day.
October in Koson averages a daily high of 24.4°C with nights around 9.8°C. Comfortable conditions for being outdoors all day.
November in Koson averages a daily high of 16.3°C with nights around 4.5°C. Comfortable conditions for being outdoors all day.
December in Koson averages a daily high of 10.4°C with nights around -1.2°C. Generally workable, with some weather to plan around.
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. Koson peaks at 94.
Based on 30 years of records, March–April scores highest for comfort in Koson, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 38.4°C.
January is the wettest, averaging —mm of rain across roughly — wet days.
January is the coolest month, with average daily highs around 9.1°C.