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As of 12:00 MDT

Weather in Grannis, MT

72°Current weather

Grannis, Thursday, 8 October, 12:00

Mostly clear. Feels like 70°. High 77°, low 40°.

Pressure30.06 inHg
Wind5.7 mph N
Humidity17%
Visibility6.2 mi
Dew point28°

Monthly outlook for Grannis, MT: average high 51.7°, average low 32.5°. That is 0.9° below the climate normal for October. Precipitation is expected on 6 days (about 3.0 inches), against a normal of 4 days and 1.0 inches. The warmest day looks like 9 October (81.8°), the coolest 16 October (18.1°).

51.7°/32.5°
Average high / low
−0.9°
Below normal
6 / 4
Wet days / normal
3.0 in
Precipitation this month

Ten-day blocks vs climate normal

PeriodForecast highNormalDifference
8 October – 17 October50.5°54°-1.9°
18 October – 27 October53.7°51.2°+1.4°
28 October – 6 Novemberat normal44.3°—

October records over 66 years

83.1°1 October 2011All-time high
-12.3°10 October 2009All-time low

Climate normals and records are computed from the nearest reference point — Clyde Park (10 mi).

Fri, 0982° / 40°0Partly cloudy
82 °Partly cloudy

Grannis, Friday, 9 October

Partly cloudy. High 82°, low 40°.

Pressure29.62 inHg
Wind9.9 mph SW
Humidity20%
Visibility6.2 mi
Dew point27°
Sat, 1061° / 42°0.48Rain
61 °Rain

Grannis, Saturday, 10 October

Rain. High 61°, low 42°.

Pressure29.56 inHg
Wind12.4 mph E
Humidity34%
Visibility6.2 mi
Dew point30°
Sun, 1141° / 33°0.28Snow
41 °Snow

Grannis, Sunday, 11 October

Snow. High 41°, low 33°.

Pressure30.03 inHg
Wind11.7 mph SE
Humidity89%
Visibility2.7 mi
Dew point30°
Mon, 1234° / 29°0.6Snow
34 °Snow

Grannis, Monday, 12 October

Snow. High 34°, low 29°.

Pressure30.12 inHg
Wind6.2 mph SE
Humidity98%
Visibility2.7 mi
Dew point30°
Tue, 1338° / 27°0Clear
38 °Clear

Grannis, Tuesday, 13 October

Clear. High 38°, low 27°.

Pressure30.09 inHg
Wind2.1 mph SE
Humidity89%
Visibility—
Dew point31°
Wed, 1451° / 33°0.46Rain
51 °Rain

Grannis, Wednesday, 14 October

Rain. High 51°, low 33°.

Pressure29.59 inHg
Wind4.2 mph W
Humidity73%
Visibility—
Dew point41°
Thu, 1536° / 28°0.64Snow
36 °Snow

Grannis, Thursday, 15 October

Snow. High 36°, low 28°.

Pressure30.39 inHg
Wind16.1 mph NW
Humidity79%
Visibility—
Dew point28°
Fri, 1639° / 18°0Clear
39 °Clear

Grannis, Friday, 16 October

Clear. High 39°, low 18°.

Pressure30.62 inHg
Wind6.5 mph SW
Humidity67%
Visibility—
Dew point21°
Sat, 1748° / 26°0Clear
48 °Clear

Grannis, Saturday, 17 October

Clear. High 48°, low 26°.

Pressure30.18 inHg
Wind7.6 mph W
Humidity60%
Visibility—
Dew point30°
Sun, 1852° / 32°0Clear
52 °Clear

Grannis, Sunday, 18 October

Clear. High 52°, low 32°.

Pressure30.06 inHg
Wind10.4 mph W
Humidity52%
Visibility—
Dew point30°
Mon, 1957° / 34°0Partly cloudy
57 °Partly cloudy

Grannis, Monday, 19 October

Partly cloudy. High 57°, low 34°.

Pressure30.12 inHg
Wind12.5 mph SW
Humidity44%
Visibility—
Dew point29°
Tue, 2060° / 36°0Clear
60 °Clear

Grannis, Tuesday, 20 October

Clear. High 60°, low 36°.

Pressure30.21 inHg
Wind11.4 mph W
Humidity38%
Visibility—
Dew point28°
Wed, 2154° / 38°0Partly cloudy
54 °Partly cloudy

Grannis, Wednesday, 21 October

Partly cloudy. High 54°, low 38°.

Pressure30.21 inHg
Wind21.6 mph W
Humidity30%
Visibility—
Dew point21°
Thu, 2257° / 34°0Overcast
57 °Overcast

Grannis, Thursday, 22 October

Overcast. High 57°, low 34°.

Pressure30.06 inHg
Wind7.8 mph SW
Humidity25%
Visibility—
Dew point12°
Fri, 2343° / 29°0.56Snow
43 °Snow

Grannis, Friday, 23 October

Snow. High 43°, low 29°.

Pressure29.83 inHg
Wind11.2 mph NW
Humidity89%
Visibility—
Dew point31°
From day 17 onward the outlook is built from 60-year climate statistics
Sat, 2450° / 31°0.04Climate normal
50 °Climate normal

Grannis, Saturday, 24 October

Climate normal for this date — 60-year average.

Average high50°
Average low31°
Average precipitation0.04 in
Chance of precipitation28%
Record high65° (1992)
Record low8° (2020)
Sun, 2550° / 31°0.04Climate normal
50 °Climate normal

Grannis, Sunday, 25 October

Climate normal for this date — 60-year average.

Average high50°
Average low31°
Average precipitation0.04 in
Chance of precipitation22%
Record high68° (2014)
Record low0° (2020)
Mon, 2649° / 31°0.07Climate normal
49 °Climate normal

Grannis, Monday, 26 October

Climate normal for this date — 60-year average.

Average high49°
Average low31°
Average precipitation0.07 in
Chance of precipitation35%
Record high65° (1999)
Record low-4° (2020)
Tue, 2748° / 29°0.04Climate normal
48 °Climate normal

Grannis, Tuesday, 27 October

Climate normal for this date — 60-year average.

Average high48°
Average low29°
Average precipitation0.04 in
Chance of precipitation25%
Record high68° (2024)
Record low2° (2019)
Wed, 2847° / 29°0.06Climate normal
47 °Climate normal

Grannis, Wednesday, 28 October

Climate normal for this date — 60-year average.

Average high47°
Average low29°
Average precipitation0.06 in
Chance of precipitation27%
Record high65° (1987)
Record low4° (1971)
Thu, 2945° / 28°0.06Climate normal
45 °Climate normal

Grannis, Thursday, 29 October

Climate normal for this date — 60-year average.

Average high45°
Average low28°
Average precipitation0.06 in
Chance of precipitation28%
Record high65° (1987)
Record low-8° (2019)
Fri, 3045° / 27°0.04Climate normal
45 °Climate normal

Grannis, Friday, 30 October

Climate normal for this date — 60-year average.

Average high45°
Average low27°
Average precipitation0.04 in
Chance of precipitation25%
Record high66° (1987)
Record low-10° (1972)
Sat, 3144° / 26°0.06Climate normal
44 °Climate normal

Grannis, Saturday, 31 October

Climate normal for this date — 60-year average.

Average high44°
Average low26°
Average precipitation0.06 in
Chance of precipitation27%
Record high64° (2014)
Record low-12° (2002)
Sun, 0144° / 26°0.06Climate normal
44 °Climate normal

Grannis, Sunday, 1 November

Climate normal for this date — 60-year average.

Average high44°
Average low26°
Average precipitation0.06 in
Chance of precipitation25%
Record high67° (2025)
Record low-3° (1989)
Mon, 0243° / 26°0.03Climate normal
43 °Climate normal

Grannis, Monday, 2 November

Climate normal for this date — 60-year average.

Average high43°
Average low26°
Average precipitation0.03 in
Chance of precipitation25%
Record high61° (2020)
Record low-10° (1995)
Tue, 0344° / 27°0.04Climate normal
44 °Climate normal

Grannis, Tuesday, 3 November

Climate normal for this date — 60-year average.

Average high44°
Average low27°
Average precipitation0.04 in
Chance of precipitation22%
Record high63° (2020)
Record low-1° (1995)
Wed, 0444° / 27°0.05Climate normal
44 °Climate normal

Grannis, Wednesday, 4 November

Climate normal for this date — 60-year average.

Average high44°
Average low27°
Average precipitation0.05 in
Chance of precipitation30%
Record high61° (2020)
Record low-6° (1973)
Thu, 0544° / 27°0.06Climate normal
44 °Climate normal

Grannis, Thursday, 5 November

Climate normal for this date — 60-year average.

Average high44°
Average low27°
Average precipitation0.06 in
Chance of precipitation38%
Record high66° (2020)
Record low-5° (2003)
Fri, 0643° / 26°0.05Climate normal
43 °Climate normal

Grannis, Friday, 6 November

Climate normal for this date — 60-year average.

Average high43°
Average low26°
Average precipitation0.05 in
Chance of precipitation27%
Record high62° (1999)
Record low2° (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 Grannis, 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 Grannis, 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.