You could have poor circulation.
Naturally it is going to be weaker than in your arms, because they are furthest away from your heart. If your feet are getting cold as a result, then you should go and see your doctor. I suffer from blood clots, and my foot was like ice because there wasn't any blood getting to it, but I'm not saying that this is what is wrong with you. Just that you should see a doctor about it. Hope this helps.