Climate Overview
The climate in San Francisco la Unión is warm and mild. The average annual temperature is 18°C and approximately 3299mm of precipitation falls per year. San Francisco la Unión receives a notable amount of rainfall throughout the year, including during its driest month. San Francisco la Unión is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: May, July, August. The coldest months are February, January, December, when temperatures can drop to 13°C.
Temperature
San Francisco la Unión has relatively stable temperatures year-round, staying within a 10°C range. May is the warmest month, though highs remain moderate at 23°C with a mean of 19°C. February is the coolest month, with minimum temperatures around 13°C and an average of 17°C. Daily temperature variation is modest, with an average difference of 7°C between highs and lows.
Precipitation
San Francisco la Unión is a very wet location, receiving approximately 3299mm of precipitation annually, which averages out to around 275mm per month. The wettest month is May, averaging 592mm of rainfall. June and September also tend to see above-average precipitation. The driest month is January, with just 31mm. That's 561mm 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 Francisco la Unión 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 October, with average winds dropping to 7km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 3km/h between the calmest and windiest months.
Seasons
89 days until Summer
It is currently spring in San Francisco la Unión, which began on March 20, 2026. San Francisco la Unión 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 May at around 23°C, while the coldest stretch bottoms out in February near 13°C. Summer is next, beginning on June 21, 2026 — 89 days from now.
Spring
Temperatures range from 14 to 23°C. Rainfall is heavy, totalling around 1001mm across the season with a monthly average of 334mm. Winds are generally light, averaging 8km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 16 to 23°C. Rainfall is heavy, totalling around 1180mm across the season with a monthly average of 393mm. Winds are generally light, averaging 8km/h. Comfortable clothing with a light layer for cooler evenings is all you need.
Autumn
Temperatures range from 15 to 22°C. Rainfall is heavy, totalling around 999mm across the season with a monthly average of 333mm. 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 22°C. Rainfall is relatively light, with around 118mm over the season and a monthly average of 39mm. 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 Francisco la Unión is during January, February and December, when the weather is most comfortable for travellers. During these months, average temperatures hover around 17°C with modest rainfall averaging 39mm per month. By contrast, May can be uncomfortably hot with temperatures reaching 23°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 Francisco la Unión 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.
