| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 4.2° | -2.3° | 35.3mm | 12 | 19 |
| February | 7.2° | -2.6° | 35.6mm | 10.3 | 32 |
| March | 10.6° | -0.6° | 44.6mm | 13.7 | 39 |
| April | 17.2° | 3.5° | 44.6mm | 11.2 | 69 |
| May | 21.9° | 7.7° | 75.1mm | 13.8 | 72 |
| June | 25.4° | 11.2° | 98.4mm | 13.7 | 73 |
| July | 29.2° | 13° | 36mm | 6.4 | 78 |
| August | 29.1° | 13.2° | 46.2mm | 5.7 | 80 |
| September | 24.2° | 9.3° | 41.4mm | 7.9 | 84 |
| October | 18.3° | 5.7° | 35.3mm | 9.1 | 76 |
| November | 11.9° | 1° | 22.8mm | 7.7 | 57 |
| December | 5.6° | -1.9° | 34.5mm | 11.1 | 26 |
January in Kastamonu averages a daily high of 4.2°C with nights around -2.3°C. Expect roughly 12 wet days totalling 35.3mm. A hard month to visit for comfort alone.
February in Kastamonu averages a daily high of 7.2°C with nights around -2.6°C. Expect roughly 10.3 wet days totalling 35.6mm. A hard month to visit for comfort alone.
March in Kastamonu averages a daily high of 10.6°C with nights around -0.6°C. Expect roughly 13.7 wet days totalling 44.6mm. Demanding conditions — pack for it and plan indoor options.
April in Kastamonu averages a daily high of 17.2°C with nights around 3.5°C. Expect roughly 11.2 wet days totalling 44.6mm. Generally workable, with some weather to plan around.
May in Kastamonu averages a daily high of 21.9°C with nights around 7.7°C. Expect roughly 13.8 wet days totalling 75.1mm. Generally workable, with some weather to plan around.
June in Kastamonu averages a daily high of 25.4°C with nights around 11.2°C. Expect roughly 13.7 wet days totalling 98.4mm. Generally workable, with some weather to plan around.
July in Kastamonu averages a daily high of 29.2°C with nights around 13°C. Expect roughly 6.4 wet days totalling 36mm. Comfortable conditions for being outdoors all day.
August in Kastamonu averages a daily high of 29.1°C with nights around 13.2°C. Expect roughly 5.7 wet days totalling 46.2mm. Comfortable conditions for being outdoors all day.
September in Kastamonu averages a daily high of 24.2°C with nights around 9.3°C. Expect roughly 7.9 wet days totalling 41.4mm. Comfortable conditions for being outdoors all day.
October in Kastamonu averages a daily high of 18.3°C with nights around 5.7°C. Expect roughly 9.1 wet days totalling 35.3mm. Comfortable conditions for being outdoors all day.
November in Kastamonu averages a daily high of 11.9°C with nights around 1°C. Expect roughly 7.7 wet days totalling 22.8mm. Generally workable, with some weather to plan around.
December in Kastamonu averages a daily high of 5.6°C with nights around -1.9°C. Expect roughly 11.1 wet days totalling 34.5mm. 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. Kastamonu peaks at 84.
Based on 30 years of records, July–October scores highest for comfort in Kastamonu, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 29.2°C.
June is the wettest, averaging 98.4mm of rain across roughly 13.7 wet days.
January is the coolest month, with average daily highs around 4.2°C.