Denver is forecast to start Monday damp and gray, with light rain and patchy fog in parts of the metro. Skies should brighten later, with a high near 56 degrees, according to the National Weather Service.
A warmer stretch follows
The forecast turns sunnier and milder Tuesday, with a high near 69 degrees. Highs are expected near 70 Wednesday, 68 Thursday and 69 Friday, with mostly sunny skies Wednesday and Thursday and partly sunny skies Friday, according to the NWS forecast.
For broad seasonal context, the National Weather Service Boulder lists Denver’s October mean temperature as 51.1 degrees for 1991–2020. That is a monthly mean, not a normal daytime high, so it is not a direct measure of how unusual a forecast high near 70 is.
Halloween climate records are context, not a forecast
The National Weather Service’s Denver Halloween climate data list an average high of 57.1 degrees and low of 31.4. The recorded Halloween temperature extremes are 79 degrees in 2016 and 1950, and 7 degrees in 2019. These long-term averages and past records describe Halloween weather history; they do not predict conditions for this year.
The Monday rain also has a broader monthly benchmark: an NWS Boulder October 2025 summary lists Denver’s normal October precipitation as 0.99 inches. That monthly figure does not indicate how much rain this particular system will bring.
