When is it too cold to bike to school?

I've been doing at this point I follow?

Keep going. My bike club has a rule "If the temperature is above 40 degrees and dry: you travel. Riding in cold weather is not so bad, provided you follow rule-couple: Dress in layers, covers over their shoes for cycling, cycling jacket heavy and / or rain gear, headband with ear protection or a baklava, cover Helment, glasses or Shields and bicycles that are used only as second-hand bike / beater. I would also recommend studded tires. Winter for cycling is a time for training, preparation, and be ready for next year.

Super Pocket Bike Cold Start After Sitting In the basement