Climate Overview
The climate in San Marcos is warm and mild. The average annual temperature is 19°C and approximately 2738mm of precipitation falls per year. June is the wettest month, receiving around 510mm of rainfall. San Marcos is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: March, April, May. The coldest months are January, February, December, when temperatures can drop to 13°C.
Temperature
San Marcos sees moderate temperature variation throughout the year, ranging from 13°C to 25°C. March is the warmest month, though highs remain moderate at 25°C with a mean of 19°C. January is the coolest month, with minimum temperatures around 13°C and an average of 18°C. On average, daily temperatures fluctuate by about 9°C between overnight lows and afternoon highs.
Precipitation
San Marcos is a very wet location, receiving approximately 2738mm of precipitation annually, which averages out to around 228mm per month. The wettest month is June, averaging 510mm of rainfall. September and August also tend to see above-average precipitation. The driest month is February, with just 25mm. That's 485mm less than June, 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 8km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is February, averaging 10km/h, though still comfortable for most outdoor activities. The calmest conditions occur in July, with average winds dropping to 7km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 3km/h gap between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 9km/h in winter, 9km/h in spring, 7km/h in summer, 7km/h in autumn.
Seasons
89 days until Summer
It is currently spring in San Marcos, which began on March 20, 2026. San Marcos is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in March at around 25°C, while the coldest stretch bottoms out in January near 13°C. Summer is next, beginning on June 21, 2026 — 89 days from now.
Spring
Temperatures range from 14 to 25°C. Rainfall is heavy, totalling around 548mm across the season with a monthly average of 183mm. Winds are generally light, averaging 9km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 16 to 24°C. Rainfall is heavy, totalling around 1170mm across the season with a monthly average of 390mm. Winds are generally light, averaging 7km/h. Comfortable clothing with a light layer for cooler evenings is all you need.
Autumn
Temperatures range from 15 to 24°C. Rainfall is heavy, totalling around 917mm across the season with a monthly average of 306mm. Winds are generally light, averaging 7km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 13 to 24°C. Rainfall is relatively light, with around 103mm over the season and a monthly average of 34mm. Winds are generally light, averaging 9km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Best Time to Visit
The best time to visit San Marcos is during January, February, March and December, when the weather is most comfortable for travellers. During these months, average temperatures hover around 18°C with modest rainfall averaging 45mm per month. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.
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.
