My cat is suddenly soiling in the house?

We are experiencing unusually cold weather at the moment - the ground is literally frozen and there is A LOT of ice. Why I am saying this is because I think it MIGHT be the reason my 4 year old neutered male cat is soiling in the house for the last 3 days - my sister who lives near me said one of her cats soiled in her kitchen - which is out of character for both our felines. My male cat is acting VERY strange, he is normally a very confident, dominant cat that is gregariousous and loveable. Over that last few days he is showing signs of fear - cowering behind things and sulking around. He is eating and doesn't seem sick - just mentally off kilter. Could this be because he has never seen this cold weather before - It's been the coldest dec/Jan in 30 years - we don't normally have frozen soil - I am wondering if he is afraid of the weather - HAS ANYONE EXPERIENCED SOMETHING SIMILAR?