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As of 15:01 MDT

Weather in Grannis, MT

83°Current weather

Grannis, Friday, 9 October, 15:01

Mostly clear. Feels like 80°. High 83°, low 42°.

Pressure29.47 inHg
Wind25.3 mph SW
Humidity12%
Visibility6.2 mi
Dew point27°

Monthly outlook for Grannis, MT: average high 58.3°, average low 37.1°. That is 2.9° above the climate normal for October. Precipitation is expected on 3 days (about 0.9 inches), against a normal of 4 days and 0.9 inches. The warmest day looks like 9 October (83°), the coolest 13 October (27.2°).

58.3°/37.1°
Average high / low
+2.9°
Above normal
3 / 4
Wet days / normal
0.9 in
Precipitation this month

Ten-day blocks vs climate normal

PeriodForecast highNormalDifference
9 October – 18 October55.7°53.6°+1.2°
19 October – 28 October62.5°50.6°+6.6°
29 October – 7 Novemberat normal43.8°—

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).

Sat, 1060° / 37°0.44Rain
60 °Rain

Grannis, Saturday, 10 October

Rain. High 60°, low 37°.

Pressure29.56 inHg
Wind11.5 mph SE
Humidity49%
Visibility6.2 mi
Dew point38°
Sun, 1139° / 29°0.23Snow
39 °Snow

Grannis, Sunday, 11 October

Snow. High 39°, low 29°.

Pressure29.94 inHg
Wind10.1 mph SE
Humidity92%
Visibility2.0 mi
Dew point36°
Mon, 1238° / 30°0.26Snow
38 °Snow

Grannis, Monday, 12 October

Snow. High 38°, low 30°.

Pressure30.06 inHg
Wind1.7 mph N
Humidity85%
Visibility6.2 mi
Dew point30°
Tue, 1349° / 27°0Clear
49 °Clear

Grannis, Tuesday, 13 October

Clear. High 49°, low 27°.

Pressure30.09 inHg
Wind4.3 mph NW
Humidity67%
Visibility0.6 mi
Dew point31°
Wed, 1454° / 33°0Overcast
54 °Overcast

Grannis, Wednesday, 14 October

Overcast. High 54°, low 33°.

Pressure30.15 inHg
Wind3.7 mph NW
Humidity61%
Visibility—
Dew point31°
Thu, 1552° / 33°0Overcast
52 °Overcast

Grannis, Thursday, 15 October

Overcast. High 52°, low 33°.

Pressure30.30 inHg
Wind10 mph W
Humidity61%
Visibility—
Dew point33°
Fri, 1650° / 35°0Partly cloudy
50 °Partly cloudy

Grannis, Friday, 16 October

Partly cloudy. High 50°, low 35°.

Pressure30.56 inHg
Wind6.1 mph NW
Humidity63%
Visibility—
Dew point31°
Sat, 1765° / 38°0Overcast
65 °Overcast

Grannis, Saturday, 17 October

Overcast. High 65°, low 38°.

Pressure30.18 inHg
Wind8 mph W
Humidity34%
Visibility—
Dew point28°
Sun, 1867° / 42°0Overcast
67 °Overcast

Grannis, Sunday, 18 October

Overcast. High 67°, low 42°.

Pressure30.12 inHg
Wind8.1 mph SW
Humidity32%
Visibility—
Dew point28°
Mon, 1970° / 42°0Clear
70 °Clear

Grannis, Monday, 19 October

Clear. High 70°, low 42°.

Pressure30.03 inHg
Wind7.6 mph SW
Humidity28%
Visibility—
Dew point27°
Tue, 2071° / 43°0Clear
71 °Clear

Grannis, Tuesday, 20 October

Clear. High 71°, low 43°.

Pressure30.00 inHg
Wind9.9 mph SW
Humidity32%
Visibility—
Dew point31°
Wed, 2159° / 41°0Clear
59 °Clear

Grannis, Wednesday, 21 October

Clear. High 59°, low 41°.

Pressure30.18 inHg
Wind5.6 mph E
Humidity51%
Visibility—
Dew point33°
Thu, 2266° / 43°0Light rain
66 °Light rain

Grannis, Thursday, 22 October

Light rain. High 66°, low 43°.

Pressure29.74 inHg
Wind18.7 mph SW
Humidity31%
Visibility—
Dew point30°
Fri, 2355° / 39°0Overcast
55 °Overcast

Grannis, Friday, 23 October

Overcast. High 55°, low 39°.

Pressure29.88 inHg
Wind8.4 mph SW
Humidity48%
Visibility—
Dew point31°
Sat, 2453° / 37°0Overcast
53 °Overcast

Grannis, Saturday, 24 October

Overcast. High 53°, low 37°.

Pressure30.06 inHg
Wind5.9 mph E
Humidity51%
Visibility—
Dew point28°
From day 17 onward the outlook is built from 60-year climate statistics
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)
Sat, 0742° / 26°0.04Climate normal
42 °Climate normal

Grannis, Saturday, 7 November

Climate normal for this date — 60-year average.

Average high42°
Average low26°
Average precipitation0.04 in
Chance of precipitation33%
Record high61° (1999)
Record low1° (2017)

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.