The City of Gallup and a portion of McKinley County are located on the Colorado Plateau, an area of high desert country. The elevation at Gallup is approximately 6,515 feet above sea level. In Gallup, the summers are warm, the winters are freezing and windy, and it is dry and mostly clear year-round. It is sunny in Gallup about 280 days a year.
The rainy period of the year lasts for 4.5 months, from June 27 to November 12, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around August 3, with an average total accumulation of 1.4 inches. The rainless period of the year lasts for 7.5 months, from November 12 to June 27. The least rain falls around June 3, with an average total accumulation of 0.3 inches. The sliding 31-day liquid-equivalent quantity of snowfall in Gallup does not vary significantly over the course of the year, staying within 0.1 inches of 0.1 inches throughout.
The length of the day in Gallup varies significantly over the course of the year. In 2017, the shortest day is December 21, with 9 hours, 45 minutes of daylight; the longest day is June 21, with 14 hours, 34 minutes of daylight.
The average hourly wind speed in Gallup experiences mild seasonal variation over the course of the year. The windier part of the year lasts for 4.9 months, from January 29 to June 27, with average wind speeds of more than 5.1 miles per hour. The windiest day of the year is April 10, with an average hourly wind speed of 6.5 miles per hour. The calmer time of year lasts for 7.1 months, from June 27 to January 29. The calmest day of the year is August 15, with an average hourly wind speed of 3.6 miles per hour.