Climate Overview
The climate in San Juan is warm and mild. The average annual temperature is 21°C and approximately 2689mm of precipitation falls per year. October is the wettest month, receiving around 523mm of rainfall. San Juan sits near the equator, so seasonal temperature differences are minimal throughout the year.
Temperature
San Juan has relatively stable temperatures year-round, staying within a 9°C range. The warmest month is April, when average highs reach 26°C and the mean temperature sits around 21°C. February is the coolest month, with minimum temperatures around 17°C and an average of 20°C. Daily temperature variation is modest, with an average difference of 7°C between highs and lows.
Precipitation
San Juan is a very wet location, receiving approximately 2689mm of precipitation annually, which averages out to around 224mm per month. The wettest month is October, averaging 523mm of rainfall. September and June also tend to see above-average precipitation. The driest month is February, with just 16mm. That's 507mm 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 Juan is relatively calm, with an average annual wind speed of 9km/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 12km/h, though still comfortable for most outdoor activities. The calmest conditions occur in October, 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 5km/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 12km/h in winter, 9km/h in spring, 8km/h in summer, 7km/h in autumn.
Seasons
89 days until Summer
It is currently spring in San Juan, which began on March 20, 2026. San Juan sits near the equator, so the traditional four-season cycle is less pronounced — temperatures remain relatively stable year-round. The warmest period peaks in April at around 26°C, while the coldest stretch bottoms out in February near 17°C. Summer is next, beginning on June 21, 2026 — 89 days from now.
Spring
Temperatures range from 17 to 26°C. Rainfall is heavy, totalling around 411mm across the season with a monthly average of 137mm. Winds are generally light, averaging 9km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 18 to 25°C. Rainfall is heavy, totalling around 943mm across the season with a monthly average of 314mm. Winds are generally light, averaging 8km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 18 to 25°C. Rainfall is heavy, totalling around 1233mm across the season with a monthly average of 411mm. Winds are generally light, averaging 7km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 17 to 25°C. Rainfall is relatively light, with around 102mm over the season and a monthly average of 34mm. Winds are generally light, averaging 12km/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 Juan is during January, February, March, April and December, when the weather is most comfortable for travellers. During these months, average temperatures hover around 21°C with modest rainfall averaging 38mm 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 Juan 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.
