As of 18:06 MDT

Weather in Big Sag, MT

47°

Big Sag, Thursday, 15 October, 18:06

Clear. Feels like 47°. High 49°, low 35°.

Pressure30.65 inHg

Wind1.2 mph E

Humidity49%

Visibility6.2 mi

Dew point30°

See detailed hourly forecast

Fri, 1666° / 36°

66 °

Big Sag, Friday, 16 October

Partly cloudy. High 66°, low 36°.

Pressure30.30 inHg

Wind1.7 mph NW

Humidity38%

Visibility6.2 mi

Dew point37°

Sat, 1773° / 48°

73 °

Big Sag, Saturday, 17 October

Overcast. High 73°, low 48°.

Pressure29.88 inHg

Wind18 mph SW

Humidity24%

Visibility6.2 mi

Dew point31°

Sun, 1862° / 44°

62 °

Big Sag, Sunday, 18 October

Clear. High 62°, low 44°.

Pressure30.06 inHg

Wind6.7 mph E

Humidity46%

Visibility6.2 mi

Dew point37°

Mon, 1962° / 38°

62 °

Big Sag, Monday, 19 October

Overcast. High 62°, low 38°.

Pressure29.91 inHg

Wind3.6 mph NE

Humidity61%

Visibility6.2 mi

Dew point40°

Tue, 2064° / 44°

64 °

Big Sag, Tuesday, 20 October

Overcast. High 64°, low 44°.

Pressure29.91 inHg

Wind4.8 mph SW

Humidity51%

Visibility—

Dew point39°

Wed, 2159° / 41°

59 °

Big Sag, Wednesday, 21 October

Mostly clear. High 59°, low 41°.

Pressure29.91 inHg

Wind5.1 mph NE

Humidity55%

Visibility—

Dew point36°

Thu, 2258° / 50°

0.23

58 °

Big Sag, Thursday, 22 October

Rain. High 58°, low 50°.

Pressure29.71 inHg

Wind9 mph W

Humidity68%

Visibility—

Dew point46°

Fri, 2354° / 44°

54 °

Big Sag, Friday, 23 October

Mostly clear. High 54°, low 44°.

Pressure29.91 inHg

Wind12.5 mph SW

Humidity53%

Visibility—

Dew point34°

Sat, 2446° / 37°

0.28

46 °

Big Sag, Saturday, 24 October

Snow. High 46°, low 37°.

Pressure30.39 inHg

Wind10.3 mph NW

Humidity59%

Visibility—

Dew point28°

Sun, 2551° / 33°

51 °

Big Sag, Sunday, 25 October

Clear. High 51°, low 33°.

Pressure30.33 inHg

Wind8.5 mph SW

Humidity41%

Visibility—

Dew point22°

Mon, 2656° / 39°

56 °

Big Sag, Monday, 26 October

Overcast. High 56°, low 39°.

Pressure29.80 inHg

Wind21.2 mph SW

Humidity32%

Visibility—

Dew point23°

Tue, 2756° / 46°

0.04

56 °

Big Sag, Tuesday, 27 October

Light rain. High 56°, low 46°.

Pressure29.88 inHg

Wind15.7 mph SW

Humidity51%

Visibility—

Dew point37°

Wed, 2857° / 38°

0.07

57 °

Big Sag, Wednesday, 28 October

Snow. High 57°, low 38°.

Pressure29.83 inHg

Wind23.8 mph W

Humidity51%

Visibility—

Dew point38°

Thu, 2954° / 35°

54 °

Big Sag, Thursday, 29 October

Overcast. High 54°, low 35°.

Pressure30.18 inHg

Wind21.9 mph SW

Humidity31%

Visibility—

Dew point19°

Fri, 3055° / 37°

55 °

Big Sag, Friday, 30 October

Mostly clear. High 55°, low 37°.

Pressure30.24 inHg

Wind7.6 mph S

Humidity39%

Visibility—

Dew point23°

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 Big Sag, 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 Big Sag, 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.