Warm, wet weather on the horizon: What Colorado's September weather could bring
September marks the transition from summer to fall in Colorado, but this year is expected to start on the warmer side.
The average high temperature in Denver during September is around 80 degrees, while the average low is about 50 degrees. Long-range forecasts are pointing toward a warmer-than-average month across much of the state.
The latest NOAA Climate Prediction Center outlook also favors above-normal temperatures across the western United States, with some of the strongest odds for warmer-than-normal conditions in the northern Rockies and Intermountain West.
September typically averages about 1.35 inches of precipitation in Denver, making it the sixth-wettest month of the year. This year, there are signs Colorado could be wetter than average. Long-range models are pointing toward wetter-than-normal conditions across the state during September, October and November.
That would be welcome news following a summer that has featured significant heat and dry conditions across parts of Colorado.
Snow is not unusual in Colorado during September, particularly in the mountains. Denver averages about 1 inch of snow during the month, making September the ninth-snowiest month of the year. Most of the state will remain focused on rain and thunderstorms early in the month, but as temperatures cool later in September, the chances for the first measurable snow of the season will increase in the higher elevations.
One of the biggest climate factors heading into fall will be El Niño. For Colorado, that could mean a warm but increasingly active fall, with opportunities for additional precipitation as we move from September into October and November.
