Climate Overview
The climate in San Marcos is hot. The average annual temperature is 29°C and approximately 2198mm of precipitation falls per year. May is the wettest month, receiving around 288mm of rainfall. San Marcos sits near the equator, so seasonal temperature differences are minimal throughout the year.
Temperature
San Marcos sees moderate temperature variation throughout the year, ranging from 25°C to 36°C. March is the hottest month, with daytime highs reaching 36°C and an average of 30°C. November is the coolest month, with minimum temperatures around 25°C and an average of 28°C. Daily temperature variation is modest, with an average difference of 8°C between highs and lows.
Precipitation
San Marcos is a very wet location, receiving approximately 2198mm of precipitation annually, which averages out to around 183mm per month. The wettest month is May, averaging 288mm of rainfall. August and June also tend to see above-average precipitation. The driest month is February, with just 14mm. That's 274mm less than May, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.
Wind
San Marcos is relatively calm, with an average annual wind speed of 10km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is March, averaging 14km/h, though still comfortable for most outdoor activities. The calmest conditions occur in November, with average winds dropping to 8km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 6km/h gap between the calmest and windiest months.
Seasons
88 days until Summer
It is currently spring in San Marcos, which began on March 20, 2026. San Marcos sits near the equator, so the traditional four-season cycle is less pronounced — temperatures remain relatively stable year-round. The warmest period peaks in March at around 36°C, while the coldest stretch bottoms out in November near 25°C. Summer is next, beginning on June 21, 2026 — 88 days from now.
Spring
Temperatures range from 26 to 36°C. Rainfall is heavy, totalling around 541mm across the season with a monthly average of 180mm. Winds are generally light, averaging 11km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 25 to 33°C. Rainfall is heavy, totalling around 823mm across the season with a monthly average of 274mm. Winds are generally light, averaging 9km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 25 to 33°C. Rainfall is heavy, totalling around 710mm across the season with a monthly average of 237mm. Winds are generally light, averaging 9km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 25 to 36°C. Rainfall is relatively light, with around 124mm over the season and a monthly average of 41mm. Winds are generally light, averaging 11km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Monthly Climate Data
The table below shows monthly climate averages for San Marcos based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.
