The Great Sand Dunes receives an average snowfall of 37 inches , with the heaviest snowfall during March. Depending on your point of view, temperatures in the Valley could be described as delightful, invigorating, frigid, brutal or anything in between. Daily temperatures can fluctuate as much as 35 in one day, which is more than anywhere else in the United States, except dry, isolated valley locations in other western states. Springtime brings high winds that can be unstable and unusually strong in April, May and early June. Northeast winds are the strongest and have been known to exceed 90 miles per hour.
Southwest winds vary from mild to violent.
Fall is generally mild, with Indian Summer days. There are only 30-40 days a year when the clouds block the sun for most of the day. While often annoying, the pinon flies do not bite. During wet, early summer times, mosquitoes and biting gnats are common. Ticks come out around April, May and June, especially in the forest and shrub land surrounding the monument.