Any mountain in freezing conditions poses a real challenge, especially one 3560ft high.
In the Spring and Summer, Snowdon is usually a good day out in the hills, but if the weather is changeable, it can still be a challenge, due to the ferocity of the prevailing winds and driving rain it receives being so close to the Irish Sea.
Its always best to go fully prepared, and consult the various weather reports for Snowdonia, as their rarely inaccurate, giving a walker a good indication of what conditions are like on the summits.
Snowdon is like any mountain, go fully kitted out for the kind of terrain you expect, and pay close inspection to the weather reports.
Ive climbed Snowdon many times, in all weather conditions, just use a bit of common sense, do not take unnecessary risks, and keep to the chosen route, and if the weather turns nasty, never be afraid to turn around.