Johnstown receives its highest rainfall in May, while humidity peaks during winter months.
🌧️ Wettest:May — 106 mm☀️ Driest:Feb — 67 mm
💧 Humidity peaks at 89% in Jan · annual avg 80%
🌍 Climate Summary
Avg Annual Temp:49.1°F
Avg Annual Rainfall:1037 mm
Avg Humidity:80%
Data Period:1981 – 2025
Johnstown Climate Overview
Johnstown has a temperate climate with warm summers and freezing winters.
Temperatures peak in Aug and drop to their lowest in Jan,
while rainfall is highest during spring and early summer months.
Humidity remains high throughout the year, especially during winter months, creating cold and damp conditions.
📈 Yearly Trends
The warmest year in Johnstown's recorded history was 2023
(avg: 52.7°F),
while the coldest year was 1987
(avg: 46.4°F),
based on annual average temperatures.
📊 Key Climate Trends
🌡️ Johnstown's temperature shows a slight warming trend over the past decade
📈 Minimum temperatures show a slight warming trend in recent years
🌧️ Rainfall varies year-to-year without a clear long-term trend
🌡️ Annual Temperature Trend
View Range:
Average annual high/low · Last 10 years · °F
Johnstown's temperatures shows a slight warming trend over the past decade.
The highest recorded temperature reached
98.8°F in Jul 1988,
while the lowest dropped to
-21.1°F in Jan 1994.
🌧️ Annual Precipitation
View Range:
Total annual precipitation · Last 10 years · mm/year
Annual rainfall in Johnstown shows noticeable variation. Rainfall varies year-to-year without a clear long-term trend.
Based on 45 years of data (1981–2025), Aug is typically the hottest month in Johnstown, Pennsylvania, with average high temperatures around 89.6°F.
What is the coldest month in Johnstown?▼
Jan is the coldest month in Johnstown, with average low temperatures around 0.2°F.
What is the rainiest month in Johnstown?▼
May receives the most rainfall with approximately 106 mm, while Feb is the driest with 67 mm.
What was the highest temperature ever recorded in Johnstown?▼
The highest recorded temperature was 98.8°F in Jul 1988. This is part of the historical record spanning 1981–2025.
What was the lowest temperature ever recorded in Johnstown?▼
The lowest recorded temperature was -21.1°F in Jan 1994.
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 Johnstown get?▼
Johnstown receives the most sunlight in Jun with an average solar radiation of 5.83 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning, agriculture, and understanding seasonal sunshine availability in Pennsylvania.
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.