The Czech Republic is a surprisingly soft country. This also applies to the local nature - with delicate landscapes and smooth curves, and beer, humbly beating over the head, and not the one who carries the roof, and the temperament of the Czechs themselves, and of course the weather. January is the most vivid confirmation of this.
The weather in the Czech Republic in January, as a rule, comfortable, the temperature is kept in the daytime at -4 ° C . Occasionally warming also occurs when the thermometer's bar shows up to +4 ° C (and even higher) . Snow falls out, but not abundantly and not so often . Therefore, the best clothes will be a good waterproof jacket, woolen sweater, rather than quickly thickened under the Czech January rain coat or thick down jacket . In general, do not "warm", there is rarely a strong piercing winds or a cloudy minus . The probability of getting sick will be higher if you overeat and catch a cold from a draft, rather than from supercooling .
Those who plan to go on downhill skiing should not be upset - in the mountains the temperature is always higher, so there the probability of catching the plus temperature is minimal. In the Krkonoše Mountains, as a rule, at this time of year, the temperature is -6 ... -12 ° C.