Monthly outlook for Boulder, MT: average high 50.6°, average low 30.4°. That is 0.9° above the climate normal for October. Precipitation is expected on 4 days (about 0.9 inches), against a normal of 4 days and 0.8 inches. The warmest day looks like 8 October (75.6°), the coolest 13 October (15.3°).
50.6°/30.4°
Average high / low
+0.9°
Above normal
4 / 4
Wet days / normal
0.9 in
Precipitation this month
Ten-day blocks vs climate normal
Period
Forecast high
Normal
Difference
8 October – 17 October
49.4°
49.5°
-0°
18 October – 27 October
52.5°
46.7°
+3.3°
28 October – 6 November
at normal
40.4°
—
October records over 66 years
76.5°1 October 2011All-time high
-18.4°31 October 2002All-time low
Climate normals and records are computed from the nearest reference point — Basin (9 mi).
Fri, 0973° / 44°0
73 °
Boulder, Friday, 9 October
Partly cloudy. High 73°, low 44°.
Pressure29.59 inHg
Wind10.2 mph SW
Humidity25%
Visibility6.2 mi
Dew point28°
Sat, 1044° / 27°0.42
44 °
Boulder, Saturday, 10 October
Snow. High 44°, low 27°.
Pressure29.80 inHg
Wind9.4 mph N
Humidity97%
Visibility1.3 mi
Dew point34°
Sun, 1126° / 22°0.35
26 °
Boulder, Sunday, 11 October
Snow. High 26°, low 22°.
Pressure30.24 inHg
Wind8.6 mph N
Humidity97%
Visibility3.2 mi
Dew point20°
Mon, 1238° / 22°0.03
38 °
Boulder, Monday, 12 October
Light snow. High 38°, low 22°.
Pressure30.21 inHg
Wind5 mph N
Humidity93%
Visibility—
Dew point28°
Tue, 1351° / 15°0
51 °
Boulder, Tuesday, 13 October
Clear. High 51°, low 15°.
Pressure30.06 inHg
Wind6.4 mph SW
Humidity62%
Visibility—
Dew point29°
Wed, 1447° / 32°0.03
47 °
Boulder, Wednesday, 14 October
Snow. High 47°, low 32°.
Pressure29.65 inHg
Wind13.4 mph NW
Humidity40%
Visibility—
Dew point23°
Thu, 1534° / 23°0.06
34 °
Boulder, Thursday, 15 October
Light snow. High 34°, low 23°.
Pressure30.42 inHg
Wind9 mph N
Humidity62%
Visibility—
Dew point18°
Fri, 1648° / 20°0
48 °
Boulder, Friday, 16 October
Clear. High 48°, low 20°.
Pressure30.42 inHg
Wind4.7 mph W
Humidity31%
Visibility—
Dew point11°
Sat, 1757° / 31°0
57 °
Boulder, Saturday, 17 October
Overcast. High 57°, low 31°.
Pressure30.12 inHg
Wind6.2 mph W
Humidity21%
Visibility—
Dew point13°
Sun, 1860° / 37°0
60 °
Boulder, Sunday, 18 October
Overcast. High 60°, low 37°.
Pressure30.03 inHg
Wind11 mph W
Humidity28%
Visibility—
Dew point20°
Mon, 1955° / 35°0
55 °
Boulder, Monday, 19 October
Overcast. High 55°, low 35°.
Pressure30.21 inHg
Wind5.7 mph N
Humidity44%
Visibility—
Dew point26°
Tue, 2062° / 38°0
62 °
Boulder, Tuesday, 20 October
Overcast. High 62°, low 38°.
Pressure30.06 inHg
Wind9.1 mph SW
Humidity25%
Visibility—
Dew point20°
Wed, 2157° / 39°0.04
57 °
Boulder, Wednesday, 21 October
Light rain. High 57°, low 39°.
Pressure29.71 inHg
Wind23.8 mph W
Humidity35%
Visibility—
Dew point28°
Thu, 2240° / 32°0
40 °
Boulder, Thursday, 22 October
Overcast. High 40°, low 32°.
Pressure29.91 inHg
Wind21.3 mph W
Humidity46%
Visibility—
Dew point19°
Fri, 2339° / 27°0
39 °
Boulder, Friday, 23 October
Mostly clear. High 39°, low 27°.
Pressure30.03 inHg
Wind10.6 mph SW
Humidity29%
Visibility—
Dew point8°
From day 17 onward the outlook is built from 60-year climate statistics
Sat, 2446° / 27°0.04
46 °
Boulder, Saturday, 24 October
Climate normal for this date — 60-year average.
Average high46°
Average low27°
Average precipitation0.04 in
Chance of precipitation23%
Record high63° (2007)
Record low-2° (1975)
Sun, 2545° / 27°0.06
45 °
Boulder, Sunday, 25 October
Climate normal for this date — 60-year average.
Average high45°
Average low27°
Average precipitation0.06 in
Chance of precipitation25%
Record high61° (1990)
Record low-9° (2020)
Mon, 2644° / 27°0.07
44 °
Boulder, Monday, 26 October
Climate normal for this date — 60-year average.
Average high44°
Average low27°
Average precipitation0.07 in
Chance of precipitation28%
Record high60° (1966)
Record low-1° (2020)
Tue, 2744° / 25°0.04
44 °
Boulder, Tuesday, 27 October
Climate normal for this date — 60-year average.
Average high44°
Average low25°
Average precipitation0.04 in
Chance of precipitation22%
Record high59° (1983)
Record low-3° (2019)
Wed, 2843° / 25°0.06
43 °
Boulder, Wednesday, 28 October
Climate normal for this date — 60-year average.
Average high43°
Average low25°
Average precipitation0.06 in
Chance of precipitation32%
Record high59° (1968)
Record low-6° (2023)
Thu, 2941° / 24°0.05
41 °
Boulder, Thursday, 29 October
Climate normal for this date — 60-year average.
Average high41°
Average low24°
Average precipitation0.05 in
Chance of precipitation27%
Record high62° (1962)
Record low-9° (1991)
Fri, 3041° / 24°0.04
41 °
Boulder, Friday, 30 October
Climate normal for this date — 60-year average.
Average high41°
Average low24°
Average precipitation0.04 in
Chance of precipitation23%
Record high62° (1962)
Record low-5° (1991)
Sat, 3140° / 24°0.05
40 °
Boulder, Saturday, 31 October
Climate normal for this date — 60-year average.
Average high40°
Average low24°
Average precipitation0.05 in
Chance of precipitation30%
Record high59° (2014)
Record low-18° (2002)
Sun, 0140° / 24°0.06
40 °
Boulder, Sunday, 1 November
Climate normal for this date — 60-year average.
Average high40°
Average low24°
Average precipitation0.06 in
Chance of precipitation23%
Record high59° (2025)
Record low-7° (2002)
Mon, 0240° / 24°0.04
40 °
Boulder, Monday, 2 November
Climate normal for this date — 60-year average.
Average high40°
Average low24°
Average precipitation0.04 in
Chance of precipitation30%
Record high58° (1981)
Record low-24° (1991)
Tue, 0340° / 24°0.04
40 °
Boulder, Tuesday, 3 November
Climate normal for this date — 60-year average.
Average high40°
Average low24°
Average precipitation0.04 in
Chance of precipitation22%
Record high59° (1962)
Record low-10° (1991)
Wed, 0440° / 24°0.05
40 °
Boulder, Wednesday, 4 November
Climate normal for this date — 60-year average.
Average high40°
Average low24°
Average precipitation0.05 in
Chance of precipitation37%
Record high55° (1976)
Record low-10° (1973)
Thu, 0540° / 24°0.05
40 °
Boulder, Thursday, 5 November
Climate normal for this date — 60-year average.
Average high40°
Average low24°
Average precipitation0.05 in
Chance of precipitation30%
Record high58° (1980)
Record low-5° (1961)
Fri, 0639° / 23°0.05
39 °
Boulder, Friday, 6 November
Climate normal for this date — 60-year average.
Average high39°
Average low23°
Average precipitation0.05 in
Chance of precipitation35%
Record high56° (2010)
Record low-1° (2003)
About the monthly outlook
How accurate is a 30-day forecast?
The first 16 days come from weather models — reliable for the first 3–5 days and progressively less so after that. Days 17 through 30 for Boulder, MT are built from the climate normal, the 60-year average, so they show typical weather for those dates rather than a specific forecast.
What does "above normal" mean?
We compare the forecast against the climate normal for those exact calendar days, computed from 60 years of observations. The deviation shows how much the coming month differs from a typical one.
Where do the 66-year records come from?
They are real temperature extremes recorded in Boulder, MT since 1960: the highest and lowest reading for each calendar date, with the year it happened.
How often is it updated?
The forecast portion refreshes every hour; the climate portion is based on long-term data and stays stable.