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Petroleum County Climate

Petroleum County, Montana

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec46.5°AVG °F

Avg Annual Temp

46.5°F

Annual Precip

14.8"

Annual Snowfall

43.4"

Extreme Heat Days

35

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
0.5"
0.4"
0.6"
1.5"
2.9"
2.8"
1.5"
1.3"
1.2"
1.2"
0.5"
0.5"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

4b

Minimum winter temperature range for plant survival

Growing Degree Days

2,253

Favors cool-season crops

Last spring frost (32°F): 05/16
First fall frost (32°F): 09/28

Seasonal Overview

Comfort ZoneSpring36°54°5.0"Summer63°70°5.6"Fall35°60°2.9"Winter25°27°1.4"20°40°60°80°100°

National Comparison

Warmer than 18% of US counties
Wetter than 7% of US counties
More seasonal variation than 63% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Petroleum County

Climate Verdict

Petroleum County has a cool, averaging 46.5°F annually, arid conditions receiving just 14.8 inches of precipitation annually, occasional hot days — 35.4 per year above 90°F, moderate snowfall of 43.4 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 25.0°F. summers are warm — July averages 70.4°F. The 45°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

Winter sports enthusiasts benefit from reliable snow cover for 3-4 months annually.

Regional Context

Petroleum County closely matches the Montana statewide average temperature of 43.7°F.

Climate Profile

About Petroleum County Weather

Wide Open and Cooler Than Most

A 46.5°F average keeps Petroleum County about 8 degrees below the national median. This semi-arid region is characterized by wide-open spaces and distinct seasonal shifts.

One of Montana's Warmer Hubs

The county’s 46.5°F temperature ranks comfortably above the 43.7°F Montana average. It serves as one of the state's warmer agricultural territories.

Dry Land and High Snowfall

Its 14.8 inches of precipitation is slightly lower than the state average of 15.4 inches. Despite the relative warmth, it experiences 43.4 inches of snow, surpassing its southern neighbors.

Scorching Summers and Stable Winters

Summers are hot with 35 days of extreme heat and a 70.4°F July average. Winters stay relatively mild for Montana, averaging 26.1°F from December through February.

Versatile HVAC Systems Required

Reliable climate control is necessary to bridge the gap between 90°F summer peaks and the 25.0°F January lows. Outdoor planning must also account for the significant 43.4 inches of annual snow.

Frequently Asked Questions

What is the average temperature in Petroleum County?
The average annual temperature in Petroleum County, MT is 46.5°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Petroleum County get?
Petroleum County receives an average of 14.8 inches of precipitation per year, including both rain and meltwater from snow. This is based on NOAA 30-year climate normals.
Does it snow in Petroleum County?
Yes, Petroleum County receives an average of 43.4 inches of snowfall per year according to NOAA climate normals.
How hot does Petroleum County get in summer?
The average summer temperature (June-August) in Petroleum County is 67.6°F. The county experiences an average of 35 days per year above 90°F.
How cold are winters in Petroleum County?
The average winter temperature (December-February) in Petroleum County is 26.1°F. January, typically the coldest month, averages 25.0°F.

Track your own weather in Petroleum County

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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.

Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor
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