Climate Overview
The climate in San Antonio is hot. The average annual temperature is 25°C and approximately 1375mm of precipitation falls per year. San Antonio receives a notable amount of rainfall throughout the year, including during its driest month. San Antonio is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: May, April, August. The coldest months are January, December, February, when temperatures can drop to 19°C.
Temperature
San Antonio sees moderate temperature variation throughout the year, ranging from 19°C to 33°C. The warmest month is May, when average highs reach 33°C and the mean temperature sits around 27°C. January is the coolest month, with minimum temperatures around 19°C and an average of 22°C. Daily temperature variation is modest, with an average difference of 8°C between highs and lows. The sharpest temperature change occurs between March and April, with a 2°C shift in average temperatures.
Precipitation
San Antonio is a fairly wet location, receiving approximately 1375mm of precipitation annually, which averages out to around 115mm per month. The wettest month is October, averaging 234mm of rainfall. June and September also tend to see above-average precipitation. The driest month is April, with just 52mm. That's 182mm less than October, the wettest month. Precipitation varies noticeably between seasons, with the second half (July to December) of the year generally seeing more rainfall.
Wind
San Antonio is relatively calm, with an average annual wind speed of 2km/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 3km/h, though still comfortable for most outdoor activities. The calmest conditions occur in October, with average winds dropping to 2km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 1km/h gap between the calmest and windiest months.
Seasons
91 days until Autumn
It is currently summer in San Antonio, which began on June 21, 2026. San Antonio 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 33°C, while the coldest stretch bottoms out in January near 19°C. Autumn is next, beginning on September 23, 2026 — 91 days from now.
Spring
Temperatures range from 20 to 33°C. Precipitation is moderate at around 220mm for the season, averaging 73mm per month. Winds are generally light, averaging 2km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 23 to 32°C. Rainfall is heavy, totalling around 430mm across the season with a monthly average of 143mm. Winds are generally light, averaging 2km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 21 to 32°C. Rainfall is heavy, totalling around 535mm across the season with a monthly average of 178mm. Winds are generally light, averaging 2km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 19 to 28°C. Precipitation is moderate at around 190mm for the season, averaging 63mm per month. Winds are generally light, averaging 2km/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 Antonio is during January, February, March and December, when the weather is most comfortable for travellers. During these months, average temperatures hover around 23°C with modest rainfall averaging 62mm per month. By contrast, May can be uncomfortably hot with temperatures reaching 33°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 Antonio 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.
