Planning for the weather is a good way to make your trip to Gallup relaxing and enjoyable, especially when you’re splurging. The hottest months are usually July and June, with an average temperature of 21°C, while the coldest months are January and December, with an average of 1°C. The snowiest months in Gallup are January, February, November and March, with each month seeing an average of 17 cm of snowfall.