If the planet is getting warmer then why do we have blizzards?

I think that the reason why we have blizzards if the planet is getting warmer is because there is still very cold weather in the winter, cold enough to reach below freezing point. The Earth's seasons cause the axis to tilt as it revolves around the sun and points sunlight to one direction of the earth. During the winter it is tilted away from the sun, and only one part of the earth receives the sunlight.