Weather in December in Helena, Mt

• The average temperature in Helena, Mt in December is cold at -6 °C (21.2 °F).
• Afternoons can be slightly cold with average high temperatures reaching -0.4 °C (31.3 °F).
• Overnight temperatures are generally very cold with an average low of -11.6 °C (11.1 °F).
• The mean daily temperature variation/ range in December is 11.2 °C (20.2 °F).
• Precipitation averages for December are low with 15mm (0.6 in) recorded.
• The shortest day is 8h 33' long and the longest day is 8h 48' long with an average length of 8h 37'.

Weather Trend Graph for December in Helena, Mt, Usa