Boulder, MT Monthly Weather

Jefferson County1:20 PM MDT46.24°N, 112.12°WElevation 4,908 ft
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October 2026

Sun
Mon
Tue
Wed
Thu
Fri
Sat
1Avg 65°/33°
2Avg 65°/33°
3Avg 64°/32°
476°/34°Avg 64°/32°
5Avg 63°/32°
6Avg 63°/31°
7Avg 62°/31°
8Avg 62°/30°
9Avg 61°/30°
10Avg 60°/30°
1182°/28°Avg 60°/29°
12Avg 60°/29°
13Avg 59°/29°
1446°/21°Avg 58°/28°
15Avg 58°/28°
16Avg 57°/28°
17Avg 57°/27°
1871°/19°Avg 56°/27°
1970°/19°Avg 56°/26°
20 Mostly Sunny 62°/38°Avg 55°/26°
21 Mostly Sunny 64°/42°Avg 55°/26°
22 Sunny 64°/42°Avg 54°/26°
23 Rain 46°/28°Avg 54°/25°
24 Mostly Sunny 45°/28°Avg 53°/25°
25 Slight Chance Light Snow 47°/28°Avg 53°/24°
26 Slight Chance Light Snow then Partly Sunny 48°/30°Avg 52°/24°
27 Sunny 48°/28°Avg 52°/24°
28 Cloudy 53°/27°Avg 51°/24°
29 Cloudy 43°/26°Avg 51°/23°
30Avg 50°/23°
31Avg 50°/23°
Average high69° (normal 59°)
Average low24° (normal 28°)
Warmest / coldest82° / 19°
Precipitation0.00 in (normal 0.11 in to date)
Record high today77° (2023)
Record low today11° (1987)

Observed: Boulder, 1 km away, records since 1880. Normals 1991–2020. Climate data from NOAA's Regional Climate Centers (ACIS); recent days are preliminary. Days ahead: the forecast.

Forecasts, observations and alerts in the United States come from the National Weather Service (NOAA); radar from NOAA's Multi-Radar Multi-Sensor system; satellite imagery from NASA's Global Imagery Browse Services (GIBS) and NOAA's GOES satellites; the map from the U.S. Geological Survey's National Map; air quality from AirNow (EPA and its partners); hurricane information from the National Hurricane Center; climate normals and records from NOAA's Regional Climate Centers (ACIS). Forecasts outside the United States and the UV index: MET Norway (CC BY 4.0); observations outside the U.S.: airport reports via NOAA's Aviation Weather Center. Place names: GeoNames (CC BY 4.0). Data are copied on a schedule and may lag the sources; for warnings that affect your safety, follow your local National Weather Service office and emergency officials. Weather news is drawn from the 4Conservative index and reflects what the press published. Terms of use.