Planning for the weather is a good way to make your trip to Montevideo relaxing and enjoyable, especially when you’re splurging. The hottest months are usually July and August, with an average temperature of 21°C, while the coldest months are January and February, with an average of -6°C. The snowiest months in Montevideo are March, April, February and January, with each month seeing an average of 24 cm of snowfall.