Gallatin County Climate and Average Weather
Climate of Gallatin County: average temperatures, rainfall and seasons month by month.
Climate in Gallatin County month by month
Average high, average low and total rainfall, based on three years of reanalysis data.
| Month | Avg high | Avg low | Rainfall | Rating |
|---|---|---|---|---|
| January | 33° | 14° | 0,8 in | ★★☆☆☆ |
| February | 34° | 15° | 1,6 in | ★★☆☆☆ |
| March | 48° | 26° | 1,7 in | ★★★☆☆ |
| April | 53° | 29° | 2,8 in | ★★★☆☆ |
| May | 62° | 38° | 3,1 in | ★★★★☆ |
| June | 70° | 45° | 2,0 in | ★★★★☆ |
| July | 83° | 55° | 0,5 in | ★★★★★ |
| August | 80° | 52° | 0,6 in | ★★★★★ |
| September | 71° | 46° | 1,0 in | ★★★★☆ |
| October | 56° | 34° | 1,9 in | ★★★☆☆ |
| November | 43° | 25° | 1,0 in | ★★★☆☆ |
| December | 40° | 24° | 1,4 in | ★★☆☆☆ |
Climate type: Subarctic. Source: Open-Meteo archive (ERA5).
Recent extremes in Gallatin County
Highest and lowest readings observed in the last 3 years of reanalysis data - not all-time records.
How Gallatin County compares with nearby places
Annual averages, and the difference against Gallatin County.
| Place | Distance | Avg temp | vs here | Annual rain |
|---|---|---|---|---|
| Bozeman | 0 mi | 45°F | about the same | 18 in |
| Missouri River | 79 mi | 46°F | +33°F warmer | 16 in |
| Yellowstone (UNESCO World Heritage Site) | 89 mi | 36°F | 41°F cooler | 25 in |
| Yellowstone National Park | 89 mi | 36°F | 41°F cooler | 25 in |
| Grand Teton National Park | 132 mi | 39°F | 38°F cooler | 30 in |
Best time to visit Gallatin County
Go in June, July, August and September. These months score highest on comfortable temperatures, low rainfall and useful daylight.
Hardest months: January, February and December - expect the least comfortable mix of heat, cold or rain.
What this means for Gallatin County
Today is much warmer than average for October. The forecast high of 74°F is 18.9°F above the 56°F typical for this month.
Rain is very unlikely today - plans do not need a backup.
No weather-related travel disruption is expected today. Roads and airports should run normally.
Northern Hemisphere, so peak summer falls in June to August.
The gap between the warmest and coldest month averages 78°F.
What to pack, what to skip
- Lightweight, light-coloured clothing and a refillable water bottle
- Sunglasses, a brimmed hat and SPF 30+
- Layers - the daily swing is 73°F, so mornings feel nothing like afternoons
- If your dates are flexible, avoid January, February and December - historically the least comfortable months here.
Summary
Gallatin County is a county in Montana. Gallatin County is a county in the United States. It has a population of about 125.000.
Right now it is 42°F (6°C) in Gallatin County with clear sky. It feels like 38°F. Today runs from 42°F to 74°F. Chance of precipitation is 1%. Sightseeing conditions score 8.3/10 - good conditions.
The best time to visit Gallatin County is June, July, August and September. The climate is subarctic. January, February and December tend to be the least comfortable months. July is the warmest month with average highs near 83°F, while January is the coldest with lows near 14°F.
Nearby highlights include Missouri River, Yellowstone (UNESCO World Heritage Site), Yellowstone National Park and Grand Teton National Park.
In plain terms. Today is much warmer than average for October. The forecast high of 74°F is 18.9°F above the 56°F typical for this month. The best window to be outside is roughly 1 PM to 4 PM, when temperature, rain chance and wind line up best. stargazing is the strongest bet in Gallatin County today at 10/10. No weather-related travel disruption is expected today. Roads and airports should run normally.
Compiled from this page's own data: atlas facts plus live Open-Meteo readings.
Quick facts about Gallatin County
| Type | County |
|---|---|
| State | Montana |
| Country | United States |
| Continent | North America |
| Coordinates | 45°40′37.2″N 111°2′34.4″W (45.677, -111.0429) |
| Population | 125.000 |
| Local time | 8:09 AM (UTC-06:00) |
| Best months | June, July, August and September |
| Climate | Subarctic |
Weather map for Gallatin County
Animated model layers. Pick a layer to load it.
Animated layers by Windy. For pin-level detail and nearby places, see the interactive map below.
Explore Gallatin County
Every topic we hold for this place, and the same topic for the places around it.
Climate for related places
Frequently asked questions
Where is Gallatin County?
Gallatin County is a county in Montana. Its coordinates are 45.677, -111.0429. It lies in North America.
What is the weather like in Gallatin County right now?
It is currently 42°F (6°C) with clear sky. Humidity is 64% and wind is 1 mph.
When is the best time to visit Gallatin County?
June, July, August and September offer the most comfortable conditions in Gallatin County, which has a subarctic climate. January, February and December are usually the hardest months for outdoor plans.
What time zone is Gallatin County in?
Gallatin County observes America/Denver (UTC-06:00). The local time is 8:09 AM.
How many people live in Gallatin County?
Gallatin County has a population of approximately 125.000.
What are the top things to do in Gallatin County?
Popular options include Missouri River, Yellowstone (UNESCO World Heritage Site), Yellowstone National Park, Grand Teton National Park and Grand Teton.
Related articles
Data sources and methodology
| Place data | USPOTUS Atlas dataset (us-counties) - coordinates, hierarchy and facts. |
|---|---|
| Forecast and observations | Open-Meteo (ECMWF and national models). |
| Air quality and pollen | Copernicus CAMS via Open-Meteo. US AQI scale. |
| Climate averages | ERA5 reanalysis via the Open-Meteo archive, aggregated over 3 years. |
| Official alerts | US National Weather Service. |
| Method | Scores, comparisons and advice on this page are computed from the inputs above. Distances are straight-line. Nothing is estimated where data is missing - the block is simply not shown. |
Last updated October 2, 2026 at 8:09 AM local time. Live blocks refresh every 15 minutes; climate averages monthly.
