Montana

Glacier County, Montana Climate

NOAA 1991-2020 normals for St. Mary 1 Ssw, 32.4 km from Glacier County

The warmest month is August, with an average high of 73°F; the coldest is February, with an average low of 15°F. A normal year brings 26.1 in of precipitation.

Temperature through the year

The normal daily high and low and the record for every date at Cut Bank (Awos) (CTB), since 1903. The line marks today.

Normal daily high and low temperature at Glacier County through the year, in °F, with the record for each date.-50050100150JanFebMarAprMayJunJulAugSepOctNovDec
  • Normal low
  • Normal high
  • Record high
  • Record low

Normals for Sep 24

Normal high
59°F
Normal low
37°F
Record high
92°Fin 2001
Record low
0°Fin 1926
Chance of a wet day
32%
Daylight
12 h 03 min

Month by month

Averages for 1991-2020. Wet days have at least 0.01 inch of precipitation. Freeze nights have a low of 32°F or colder; degree days are on a 65°F base. Each month links to its own page.

MonthAvg highAvg lowRecord highRecord lowPrecipitationWet daysFreeze nightsHeating DDCooling DD
January32°F15°F67°F (1962)-46°F (1918)2.07 in14.826.51,2940
February31°F15°F71°F (1992)-47°F (1936)2.06 in14.125.81,1770
March38°F20°F77°F (2004)-34°F (2002)2.50 in16.025.41,1240
April46°F28°F87°F (1910)-25°F (1935)2.45 in14.720.88480
May56°F35°F92°F (2025)9°F (1954)2.83 in12.910.76020
June63°F42°F101°F (1941)21°F (1910)3.07 in12.81.73831
July73°F46°F106°F (2007)32°F (1999)1.20 in8.10.017511
August73°F45°F107°F (1961)25°F (1910)1.28 in7.90.61968
September63°F39°F97°F (1967)-4°F (1934)1.63 in8.96.04241
October49°F32°F88°F (1992)-14°F (1919)2.17 in12.315.17640
November37°F25°F79°F (1962)-33°F (1921)2.70 in14.021.01,0200
December31°F17°F67°F (1939)-46°F (1924)2.13 in14.327.11,2760
Year49°F30°F26.09 in1511819,28221

Precipitation

Rain and melted snow together. The chance of a wet day is the share of days with at least 0.01 inch of precipitation.

26.1 in in a normal year, most in June.

Chance of a wet day

The chance of at least 0.01 inch of precipitation on each date at Glacier County, in percent.0204060JanFebMarAprMayJunJulAugSepOctNovDec
  • Chance of a wet day

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for St. Mary 1 Ssw. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around June 3 and the first fall freeze around September 8, a growing season of about 94 days.

Median at 32°F
last June 3, first September 8
Median at 28°F
last May 14, first September 25

Frost dates, growing season and degree days

Humidity and comfort

NASA POWER reanalysis, 1991-2020, for the grid cell around Glacier County.

Days with a mean dew point of 65°F or more are rare here in every month.

MonthDew pointHumidityDryComfortableHumidMuggyOppressiveMiserable
January15°F95%100%0%0%0%0%0%
February16°F93%100%0%0%0%0%0%
March22°F87%100%0%0%0%0%0%
April27°F78%100%0%0%0%0%0%
May35°F72%100%0%0%0%0%0%
June42°F72%99%1%0%0%0%0%
July46°F64%97%3%0%0%0%0%
August43°F59%100%0%0%0%0%0%
September36°F63%100%0%0%0%0%0%
October29°F74%100%0%0%0%0%0%
November21°F86%100%0%0%0%0%0%
December14°F93%100%0%0%0%0%0%

Comfort is judged by the day's mean dew point: dry below 55°F, comfortable to 60°F, humid to 65°F, muggy to 70°F, oppressive to 75°F, miserable above.

Clouds

Average share of the sky covered, from satellite (CERES and GEWEX SRB) by way of NASA POWER, 1991-2020.

The clearest month is July, with the sky 45 percent covered on average; the cloudiest is April, at 72 percent.

Wind

The mean wind speed over the whole day, from the MERRA-2 reanalysis by way of NASA POWER. Gusts run well above it.

The windiest month is January, averaging 11.6 mph at 10 meters (33 feet) above the ground.

Daylight and sunshine

The longest day is Jun 20, with 16 h 10 min of daylight; the shortest is Dec 18, with 8 h 16 min.

Hours of daylight at Glacier County through the year.0510152025JanFebMarAprMayJunJulAugSepOctNovDec
  • Day length

Solar energy

Average daily sunshine reaching the ground on a flat surface, in kilowatt-hours per square meter, clouds included.

Sunrise and sunset calendar

How Glacier County is running

NOAA NCEI Climate at a Glance, from the nClimGrid analysis of every station, updated early each month. A rank of 1 is the highest or lowest of all years since 1895.

August 2026 in Glacier County: 60.8°F (+0.5 °F against 1991-2020), the 36th warmest in 132 years on record.

August 2026 in Glacier County: 1.32 in (-0.06 in against 1991-2020), the 62nd driest in 132 years on record.

January to August 2026 in Glacier County: 44.9°F (+3.1 °F against 1991-2020), the 2nd warmest in 132 years on record.

January to August 2026 in Glacier County: 16.10 in (-0.56 in against 1991-2020), the 56th driest in 132 years on record.

Warmest August
65.4°F in 2022
Coolest August
53.1°F in 1907
Wettest August
4.98 in in 1951
Driest August
0.02 in in 1955

Every year since 1895

Each year's average temperature in Glacier County against the 1991-2020 average, in °F, 1895 to 2025.-10-50+5+101900192019401960198020002020NOAA NCEI Climate at a Glance

Montana climate and rankings

Month pages

The weather in Glacier County in each month, day by day.

What this means

A normal is the average of the thirty years 1991 to 2020, the period the World Meteorological Organization and NOAA use for comparison. It is an average, not a forecast: most days depart from it, and some by a long way.

A record is the highest or lowest value on the date in every year the station has reported, back to 1903. It rests on one station, so a neighbor a few miles away can hold different ones.

Cloud, humidity, wind and sunshine come from a reanalysis: a weather model run over the past with every observation fed in, averaged over a grid cell about 50 km across. It is consistent everywhere on Earth; it smooths local detail such as a lake shore or a valley.

More for this place

Nearby

Sources

Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00004130 (St. Mary 1 Ssw), public domain. Records: NOAA GHCN-Daily, station USW00024137, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus. Rankings: NOAA NCEI Climate at a Glance, public domain.