Climate Overview
The climate in San Marcos is hot. The average annual temperature is 27°C and approximately 2020mm of precipitation falls per year. October is the wettest month, receiving around 416mm of rainfall. San Marcos is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: April, March, May. The coldest months are January, February, December, when temperatures can drop to 22°C.
Temperature
San Marcos sees moderate temperature variation throughout the year, ranging from 22°C to 34°C. The warmest month is April, when average highs reach 34°C and the mean temperature sits around 28°C. January is the coolest month, with minimum temperatures around 22°C and an average of 26°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 2020mm of precipitation annually, which averages out to around 168mm per month. The wettest month is October, averaging 416mm of rainfall. June and September also tend to see above-average precipitation. The driest month is February, with just 3mm. That's 413mm less than October, 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 mildly breezy, with an average annual wind speed of 13km/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 19km/h, though still comfortable for most outdoor activities. The calmest conditions occur in October, with average winds dropping to 6km/h, making it an ideal period for wind-sensitive activities. Wind speeds vary significantly across the year, with a 13km/h difference between the calmest and windiest months. This level of variation is worth factoring into travel plans. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 18km/h in winter, 14km/h in spring, 12km/h in summer, 8km/h in autumn.
Seasons
87 days until Winter
It is currently autumn in San Marcos, which began on September 23, 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 April at around 34°C, while the coldest stretch bottoms out in January near 22°C. Winter is next, beginning on December 21, 2026 (87 days from now).
Spring
Temperatures range from 22 to 34°C. Precipitation is moderate at around 285mm for the season, averaging 95mm per month. Winds are generally light, averaging 14km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 23 to 31°C. Rainfall is heavy, totalling around 777mm across the season with a monthly average of 259mm. Winds are generally light, averaging 12km/h. Light, breathable clothing is ideal. Perfect conditions for outdoor activities.
Autumn
Temperatures range from 23 to 31°C. Rainfall is heavy, totalling around 923mm across the season with a monthly average of 308mm. Winds are generally light, averaging 8km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 22 to 32°C. Precipitation is minimal, with only around 35mm for the entire season. Winds are moderate at around 18km/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.
