PlainClimate
2026 data Public-data reference. official source

Great Falls, MT Climate

Temperature, precipitation, and comfort score from NOAA NCEI 1991-2020 normals →

30-year climate normals from 2 weather stations (1991-2020).

Great Falls, Montana has an average annual temperature of 45°F and a climate comfort score of 37/100 (Below Average). Annual precipitation totals 14.8", including 66.1" of snow. Based on NOAA 30-year normals (1991–2020).

Avg Temperature

45°F (7°C)

Avg High

57°F

Avg Low

32°F

Annual Precip

14.8"

Annual Snow

66.1"

Comfort Score

37/100

Below Average

Climate Comfort Score

37/100

Below Average

Avg Annual Temperature

45°F

30-year mean (NOAA NCEI)

Annual Precipitation

14.8"

Plus 66.1" of snow

Comfort score vs national 100-point ceiling (Great Falls) 37.0%
National median (≈55)

PlainClimate composite — temperature mildness, humidity, precipitation, extreme-weather frequency. Below Average for the Great Falls area.

Warming context for Great Falls

Methodology

How the U.S. land temperature anomaly tracks against the global mean since 1900. The current NOAA 1991-2020 normal for Great Falls captures average conditions across the spread shown — the most recent decade is warmer than the 30-year mean.

Warming context — U.S. vs global, with Paris reference lines Anomaly chart from 1900 to 2024. Local series shows warming of 0.11 °C per decade versus a global rate of 0.11 °C per decade (ratio 1.00). Paris Agreement thresholds at 1.5 and 2.0 °C are dashed. -1.0°C -0.5°C +0.0°C +0.5°C +1.0°C +1.5°C +2.0°C +2.5°C Paris 1.5°C Paris 2.0°C 1900192019401960198020002020
  • United States land mean (NOAA NCEI) +0.11 °C/decade
  • Global anomaly (NASA GISTEMP) +0.11 °C/decade
  • Paris Agreement thresholds 1.5°C / 2.0°C
Sources: NOAA NCEI, NASA GISTEMP. Paris thresholds per IPCC AR6 WG1.

Monthly Temperatures

Average daily high and low temperatures by month

Month Avg High Avg Low Mean
January 35°F (2°C) 15°F (-9°C) 25°F (-4°C)
February 37°F (3°C) 15°F (-9°C) 26°F (-3°C)
March 46°F (8°C) 22°F (-5°C) 34°F (1°C)
April 55°F (13°C) 30°F (-1°C) 42°F (6°C)
May 65°F (18°C) 38°F (4°C) 52°F (11°C)
June 73°F (23°C) 46°F (8°C) 59°F (15°C)
July 84°F (29°C) 51°F (11°C) 68°F (20°C)
August 83°F (28°C) 50°F (10°C) 67°F (19°C)
September 72°F (22°C) 43°F (6°C) 57°F (14°C)
October 57°F (14°C) 33°F (0°C) 45°F (7°C)
November 44°F (7°C) 24°F (-5°C) 34°F (1°C)
December 36°F (2°C) 16°F (-9°C) 26°F (-3°C)

Monthly Precipitation

Average monthly rainfall and snowfall

January 0.6"

Snow: 9.2"

6.9 days with precipitation

February 0.6"

Snow: 10.1"

8.2 days with precipitation

March 0.7"

Snow: 10.1"

8.1 days with precipitation

April 1.7"

Snow: 9.4"

10.0 days with precipitation

May 2.4"

Snow: 1.9"

11.3 days with precipitation

June 2.7"

Snow: 0.3"

11.8 days with precipitation

July 1.2"

7.1 days with precipitation

August 1.2"

Snow: 0.3"

6.8 days with precipitation

September 1.3"

Snow: 0.8"

7.1 days with precipitation

October 1.1"

Snow: 5.2"

7.4 days with precipitation

November 0.7"

Snow: 9.2"

6.5 days with precipitation

December 0.5"

Snow: 9.6"

6.5 days with precipitation

Frost Dates & Growing Season

First Fall Freeze

September 24

50% probability date

Last Spring Freeze

May 19

50% probability date

Heating & Cooling Degree Days

Annual totals indicate energy demand for heating and cooling

Heating Degree Days

7,722

Higher = more heating needed

Cooling Degree Days

310

Higher = more cooling needed

Warmest Month

July

Coldest Month

January

Humidity & Wind

Monthly averages from hourly observations

Month Humidity Wind (mph)
January 60% 13.1
February 61% 11.5
March 56% 11.6
April 52% 11.2
May 58% 9.8
June 51% 9.1
July 42% 8.8
August 42% 9.2
September 51% 10.7
October 56% 12.7
November 59% 13.7
December 61% 13.4

Related Data

Climate Guides

Climate Insight: Great Falls, MT

The NOAA 1991–2020 climate normals describe Great Falls, Montana as a location with an annual average temperature of 45°F, ranging from a mean daily high of 57°F to a mean daily low of 32°F. July is typically the warmest month of the year, while January is the coldest. These thirty-year averages, computed from 2 weather stations, smooth out year-to-year variability and give a baseline expectation for typical conditions in any given month.

Precipitation patterns matter as much as temperature for anyone planning to live, garden, or travel here. Great Falls receives roughly 14.8 inches of precipitation each year, with 66.1 inches typically falling as snow. Growing-season length varies with elevation and microclimate, with the last spring freeze near May 19 and the first fall freeze near September 24. For energy use, 7,722 heating degree days and 310 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Great Falls scores 37/100 (Below Average), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. Use the monthly tables above to plan around specific windows — shoulder seasons for mild highs and lows, peak summer for July-driven heat, or deep winter for January-driven cold. All figures here are thirty-year averages: any single year may run warmer, wetter, drier, or cooler than the normal, so treat them as planning guidance rather than forecasts.

Frequently Asked Questions

What is the average temperature in Great Falls, MT?
The average annual temperature in Great Falls, Montana is 45°F. The warmest month averages 84°F (29°C) and the coldest averages 15°F (-9°C).
How much rain does Great Falls get?
Great Falls receives 14.8 inches of precipitation annually, including 66.1 inches of snow. Based on NOAA 30-year climate normals (1991-2020).
What is the comfort score for Great Falls?
Great Falls has a climate comfort score of 37/100 (Below Average). This score considers temperature mildness, humidity, precipitation, and extreme weather frequency.
When is the growing season in Great Falls?
Growing season data is not available for Great Falls.
How much energy does heating and cooling require in Great Falls?
Great Falls has 7,722 heating degree days and 310 cooling degree days annually. Higher heating degree days indicate greater winter energy demand, while higher cooling degree days indicate greater summer cooling needs.
Where does this Great Falls climate data come from?
All climate data comes from NOAA U.S. Climate Normals v1.0.1, covering the 30-year period from 1991 to 2020. Data is collected from 2 weather stations. These 30-year averages are the standard reference for typical weather conditions.

Data Sources

Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). Station: USW00024143. For informational purposes only.

Related

Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainClimate Editorial