January in Upplands-Bro is the windiest, the cloudiest, and the most freezing month of the year. In January, the weather in Upplands-Bro is typically freezing. Average daily high temperature in January is about 1 degree below zero. On average, Upplands-Bro has 14 cloudy, 9 partly cloudy, 3 rainy, 3 sunny, and 2 snowy days in January. The rains are usually light. January as well as February, March, April, and May is considered the most uncomfortable time to visit Upplands-Bro.