San Marcos receives its highest rainfall in May, while humidity peaks during winter months.
🌧️ Wettest:May — 115 mm☀️ Driest:Feb — 47 mm
💧 Humidity peaks at 72% in Feb · annual avg 68%
🌍 Climate Summary
Avg Annual Temp:68.2°F
Avg Annual Rainfall:827 mm
Avg Humidity:68%
Data Period:1981 – 2025
San Marcos Climate Overview
San Marcos has a warm subtropical climate with warm summers and cold winters.
Temperatures peak in Aug 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 San Marcos's recorded history was 2024
(avg: 71.8°F),
while the coldest year was 1992
(avg: 64.6°F),
based on annual average temperatures.
📊 Key Climate Trends
🌡️ San Marcos's temperature shows a slight warming trend over the past decade
📈 Minimum temperatures show a slight warming trend in recent years
🌧️ Rainfall has decreased in recent years compared to earlier periods
🌡️ Annual Temperature Trend
View Range:
Average annual high/low · Last 10 years · °F
San Marcos's temperatures shows a slight warming trend over the past decade.
The highest recorded temperature reached
112.2°F in Aug 2024,
while the lowest dropped to
3.2°F in Dec 1989.
🌧️ Annual Precipitation
View Range:
Total annual precipitation · Last 10 years · mm/year
Annual rainfall in San Marcos shows noticeable variation. Rainfall has decreased in recent years compared to earlier periods.
Based on 45 years of data (1981–2025), Aug is typically the hottest month in San Marcos, Texas, with average high temperatures around 104.2°F.
What is the coldest month in San Marcos?▼
Jan is the coldest month in San Marcos, with average low temperatures around 24.5°F.
What is the rainiest month in San Marcos?▼
May receives the most rainfall with approximately 115 mm, while Feb is the driest with 47 mm.
What was the highest temperature ever recorded in San Marcos?▼
The highest recorded temperature was 112.2°F in Aug 2024. This is part of the historical record spanning 1981–2025.
What was the lowest temperature ever recorded in San Marcos?▼
The lowest recorded temperature was 3.2°F in Dec 1989.
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 San Marcos get?▼
San Marcos receives the most sunlight in Jul with an average solar radiation of 6.68 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning, agriculture, and understanding seasonal sunshine availability in Texas.
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.