Complex sentence: During a severe and prolonged cold snap in January 2010, the city recorded 12 consecutive days of low temperatures at or below and nine of the twelve days below with several mornings at or near freezing.
Split into simpler sentences: During a severe and prolonged cold snap in January 2010, the city recorded 12 consecutive days of low temperatures at or below. Nine of the twelve days were below, with several mornings at or near freezing.