Climate Overview
The climate in San Juan is hot. The average annual temperature is 27°C and approximately 878mm of precipitation falls per year. San Juan receives a notable amount of rainfall throughout the year, including during its driest month. San Juan is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, September, July. The coldest months are February, March, January, when temperatures can drop to 23°C.
Temperature
San Juan has relatively stable temperatures year-round, staying within a 7°C range. The warmest month is August, when average highs reach 30°C and the mean temperature sits around 28°C. February is the coolest month, with minimum temperatures around 23°C and an average of 25°C. Daily temperature variation is modest, with an average difference of 4°C between highs and lows.
Precipitation
San Juan is a moderately rainy area, receiving approximately 878mm of precipitation annually, which averages out to around 73mm per month. The wettest month is September, averaging 143mm of rainfall. October and November also tend to see above-average precipitation. The driest month is January, with just 32mm. That's 112mm less than September, the wettest month. Precipitation varies noticeably between seasons, with the second half (July to December) of the year generally seeing more rainfall.
Wind
San Juan is mildly breezy, with an average annual wind speed of 19km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is July, averaging 22km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in October, with average winds dropping to 15km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 7km/h gap between the calmest and windiest months.
Seasons
89 days until Summer
It is currently spring in San Juan, which began on March 20, 2026. San Juan 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 August at around 30°C, while the coldest stretch bottoms out in February near 23°C. Summer is next, beginning on June 21, 2026 — 89 days from now.
Spring
Temperatures range from 23 to 29°C. Precipitation is moderate at around 181mm for the season, averaging 60mm per month. Winds are moderate at around 20km/h. Light layers work well as temperatures warm through the season — a great time to be outdoors.
Summer
Temperatures range from 26 to 30°C. Precipitation is moderate at around 194mm for the season, averaging 65mm per month. Winds are moderate at around 21km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 25 to 30°C. Rainfall is heavy, totalling around 389mm across the season with a monthly average of 130mm. Winds are moderate at around 16km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 23 to 28°C. Rainfall is relatively light, with around 114mm over the season and a monthly average of 38mm. Winds are moderate at around 20km/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 and February, when the weather is most comfortable for travellers. During these months, average temperatures hover around 25°C with modest rainfall averaging 36mm per month. By contrast, August can be uncomfortably hot with temperatures reaching 30°C. 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.
