Pleasant temps and a potential first snow: What to expect from Colorado’s weather in September

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Usually, September is one of the most pleasant months of the year in Colorado. Some of the key features include:

  • Large snowstorms are not frequent occurrences, but elevated mountains frequently receive snowfall in the month of September.
  • September marks the conclusion of the majority of thunderstorms in Colorado.
  • Gorgeous autumn foliage comes back for a few weeks!

    • Here is a glimpse into a few of the September records in Colorado.

  • First snowfall: September 3rd (1961).
  • September with the most snowfall: 1971 (17.2 inches).
  • The driest September on record was in 1944, with only a small amount of rainfall.
  • The wettest September occurred in 2013, with 5.61 inches of precipitation at DIA, but there were even greater quantities in the northern counties of Boulder and Larimer, leading to extensive flooding.

    • Temperatures.

    In September, we experienced a day with triple-digit temperatures. On September 5th, we reached a scorching 101 degrees. Even in 2020, September can still be incredibly hot.

    The lowest temperature recorded was 17 degrees on September 29, 1985.

    By the end of the month, the average lows range from 44 degrees to 55 degrees, while the average highs in Colorado this month are 73 degrees on the last day and 85 degrees on the first day of the month.

    Severe weather.

    As the month progresses, thunderstorms can still occur infrequently, but they tend to increase in intensity. The typical threats include heavy rain, lightning, large hail, and even tornadoes.

    Should we allow it to snow?

    These are the highest seven September months with the most snowfall.

  • In 1971, the rainfall measurement recorded was 17.2 inches.
  • 1936: 16.5 inches.
  • 1959: 12.9 inches.
  • 1895: 11.4 inches.
  • 1985: 8.7 inches.
  • 1995: 7.4 inches.
  • 1908: 6.5 inches.

    • Thousands of weather watchers have reported becoming CoCoRaHs volunteers to learn what precipitation is, and you can measure the storm. While we can experience some big storms, snow generally occurs late in the month.

    Looking ahead.

    It appears that we will experience winter conditions similar to the previous two years, with the Pacific Ocean’s cooler water in the equatorial region leading to the suppression of the northwest monsoon and increased moisture as we move further south. However, this also means that the storm systems driving snowfall during the winter tend to favor the central and northern mountains of Colorado, while the southeastern region experiences it at a somewhat lesser extent.

    As we approach August, we can expect conditions in much of the western and central United States to be slightly drier and warmer than average. While recent rains have helped improve drought conditions in much of the area along Interstate 25 and just west of it, the West is still dealing with severe drought. It is handy to get any moisture we can in such circumstances.

    We are still in the fire season, so we hope for some September moisture, of course. Wildfires are influenced by dry and hot conditions, as well as wind. The outlook for the next 90 days is drier and warmer than average, which is not great news for the store conditions.