Helena receives its highest rainfall in May, while humidity peaks during winter months.
🌧️ Wettest:May — 73 mm☀️ Driest:Jan — 30 mm
💧 Humidity peaks at 91% in Jan · annual avg 71%
🌍 Climate Summary
Avg Annual Temp:40.8°F
Avg Annual Rainfall:518 mm
Avg Humidity:71%
Data Period:1981 – 2025
Helena Climate Overview
Helena has a cold continental climate with warm summers and freezing winters.
Temperatures peak in Jul and drop to their lowest in Jan,
while rainfall is highest during spring and early summer months.
Humidity remains moderate throughout the year, especially during winter months, creating cold and damp conditions.
📈 Yearly Trends
The warmest year in Helena's recorded history was 2025
(avg: 44.1°F),
while the coldest year was 1996
(avg: 36.7°F),
based on annual average temperatures.
📊 Key Climate Trends
🌡️ Helena's temperature has remained relatively stable over the past decade
📊 Minimum temperatures have remained largely stable across the dataset
🌧️ Rainfall has decreased in recent years compared to earlier periods
🌡️ Annual Temperature Trend
View Range:
Average annual high/low · Last 10 years · °F
Helena's temperatures has remained relatively stable over the past decade.
The highest recorded temperature reached
99.5°F in Jul 2002,
while the lowest dropped to
-45.7°F in Dec 1983.
🌧️ Annual Precipitation
View Range:
Total annual precipitation · Last 10 years · mm/year
Annual rainfall in Helena shows noticeable variation. Rainfall has decreased in recent years compared to earlier periods.
Based on 45 years of data (1981–2025), Jul is typically the hottest month in Helena, Montana, with average high temperatures around 90.5°F.
What is the coldest month in Helena?▼
Jan is the coldest month in Helena, with average low temperatures around -10.9°F.
What is the rainiest month in Helena?▼
May receives the most rainfall with approximately 73 mm, while Jan is the driest with 30 mm.
What was the highest temperature ever recorded in Helena?▼
The highest recorded temperature was 99.5°F in Jul 2002. This is part of the historical record spanning 1981–2025.
What was the lowest temperature ever recorded in Helena?▼
The lowest recorded temperature was -45.7°F in Dec 1983.
How many years of data does this page cover?▼
This page covers 45 years of climate data from 1981 to 2025. As new data is added to the database the page automatically reflects the updated coverage.
How much sunlight does Helena get?▼
Helena receives the most sunlight in Jul with an average solar radiation of 7.12 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning, agriculture, and understanding seasonal sunshine availability in Montana.
Where does this weather data come from?▼
All climate data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite and model data. It provides monthly averages for temperature, precipitation, humidity, wind speed, and solar radiation.
📚 Data Source
All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.