San Antonio - Weather by month Based on the period 1991-2020 (January - February - March - April - May - June - July - August - September - October - November - December) January, the coldest month of the year, is generally a mild month. The average temperature is of 11.2 °C (52 °F), with a minimum of 5 °C (41 °F) and a maximum of 17.4 °C Get the monthly weather forecast for San Antonio, TX, including daily high/low, historical averages, to help you plan ahead. .

weather in san antonio in april