October in Hanoi is the sunniest month of the year. In October, the weather in Hanoi is typically hot. Average daily high temperature in October is about 27 degrees above zero. On average, Hanoi has 21 rainy, 6 sunny, 2 cloudy, and 2 partly cloudy days in October. The rains are usually heavy. October as well as May, June, July, and August is considered the most uncomfortable time to visit Hanoi.