Union Square Weather Forecast

    • 51
    • 62

    Rain Showers Likely

    • 47
    • 68

    Partly Sunny

    • 49
    • 77

    Mostly Sunny

    • 50
    • 79

    Mostly Sunny

    • 52
    • 77

    Mostly Sunny

    • 55
    • 82

    Partly Sunny

Today 30 Sep Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County

Showers likely through the day. Slight chance of Thunderstorms in the afternoon. Highs 61 to 69. Northeast Winds 10 to 15 Mph in the afternoon. Chance of rain 70 percent.

Tonight 30 Sep Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County

Mostly cloudy. Slight chance of Showers in the evening. Lows near 50. Chance of rain 10 percent.

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Union Square Temperature Statistics

September Temperature

Broomfield / Jeffco (12.4 miles)

  • Lowest 22 September, 2026

    51.8 °F

  • Average September

    67.6 °F

  • Highest 5 September, 2026

    93.2 °F

Climate (2021–2026)

Broomfield / Jeffco (12.4 miles)

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  • Average Low 2021–2026

    42.2 °F

  • Average 2021–2026

    51.7 °F

  • Average High 2021–2026

    66 °F
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