Weather in San Antonio in January

Prime time. January is about as good as San Antonio gets. Highs average 17.7 °C, lows 5.2 °C, and rain falls on 6 days — nothing in the month is working against you.

January ranks 5 of 12 in San Antonio: past the worst of the year but short of February, which is the month to book if the dates are open.

Rain falls on only 6 days, so an itinerary with no wet-weather fallback is a reasonable risk. Pack for 17.7 °C days and 5.2 °C nights; the spread matters more here than any single number.

What the averages hide

Averages flatten a month, and this one hides a few things: 4 nights fall below freezing. Across the twenty years measured, the hottest January day reached 29.7 °C and the coldest night fell to -6 °C, and the wettest single day dropped 43 mm — roughly 88% of the month's rain in one day.

January is moderately variable: 5 mm in the driest year against 130 mm in the wettest, around an average of 49 mm. Roughly two Januarys in three land near that average, and the third does something else entirely.

Wind is light at 9.7 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 70%.

How January sits in the year

This is a turning point in the year — December and February sit on opposite sides of it, so the month contains the change rather than following it.

Daylight in January

January sits at the dark end of San Antonio's year — 10.4 hours of daylight against 14 at midsummer, gaining 0.5 hours across the month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

An inland climate

With no coast nearby, the year swings a fair way — 31.5 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.

How busy it gets

Busy. Popular without being frantic; book the things you care about, improvise the rest.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

January in San Antonio versus nearby

If San Antonio is one option among several, the nearby comparison is worth making. Corpus Christi is close enough to be a coin toss — 2.1 °C warmer, the same number of rain days. Laredo is a better bet in January — 2.9 °C warmer, 2 days less rain.

So: January works, with February the better month by 11 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in San Antonio

See all twelve months in San Antonio, or where else to go in January.