St Mary's Weather Forecast

    • 44
    • 52

    Rain Showers Likely

    • 43
    • 53

    Rain Showers Likely

    • 37
    • 50

    Rain Showers Likely

    • 36
    • 48

    Chance Thunderstorms

    • 37
    • 49

    Slight Chance Thunderstorms

    • 38
    • 51

    Chance Thunderstorms

Today 17 Sep South and Southeast Grand/West Central and Southwest Boulder/Gilpin/Clear Creek/Summit/North and Wes

Chance of rain Showers in the Morning, then rain Showers likely and chance of Thunderstorms in the afternoon. Highs 54 to 64. Chance of rain 70 percent.

Tonight 17 Sep South and Southeast Grand/West Central and Southwest Boulder/Gilpin/Clear Creek/Summit/North and Wes

Mostly cloudy. Chance of rain Showers and slight chance of Thunderstorms in the evening. Lows 38 to 48. Chance of rain 30 percent.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

St Mary's Temperature Statistics

September Temperature

Boulder Municipal Airport (26.7 miles)

  • Lowest 10 September, 2026

    53.6 °F

  • Average September

    74 °F

  • Highest 13 September, 2026

    96.8 °F

Climate (2021–2026)

Boulder Municipal Airport (26.7 miles)

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  • Average Low 2021–2026

    41.3 °F

  • Average 2021–2026

    53.7 °F

  • Average High 2021–2026

    66.4 °F
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