In October, the weather in Longueuil is typically warm. Average daily high temperature in October is about 12 degrees above zero. On average, Longueuil has 14 rainy, 7 sunny, 7 partly cloudy, and 3 cloudy days in October. The rains are usually heavy. October as well as March, April, May, and November is considered the most uncomfortable time to visit Longueuil.