Climate averages 1991–2020
San Antonio weather
in January.
A mild, moderately wet month: the coolest and the 3rd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
January is a mild month in San Antonio: daytime highs average 16.9°C and nights cool to about 6.7°C. By daytime temperature it is the coolest month of the year.
Expect about 57 mm of rain on roughly 7 days, which makes January a moderately wet month (the 3rd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 10 h 29 min on an average January day.
The nearest other city in this atlas is New Braunfels (47 km away). In January its highs average 16.4°C, about as warm as San Antonio, with 63 mm of rain.
Among the 498 cities listed in the United States, San Antonio ranks joint 101st of 498 for the warmest January highs and joint 145th of 498 for the driest January (rainfall, lowest first). The mean January high of those 498 cities is 9.5°C; San Antonio is 7.4°C warmer than that mean.
From January to February, average highs rise by 2.4°C to 19.3°C, and monthly rainfall rises from 57 mm to 59 mm.
The annual picture
January in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
San Antonio climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January, selected | 16.9°C6.7°C | 6.7°C | 57 | 7.2 | 10.510 h |
| February | 19.3°C8.7°C | 8.7°C | 59 | 7.5 | 11.111 h |
| March | 22.8°C12.1°C | 12.1°C | 79 | 9.2 | 12.012 h |
| April | 26.6°C15.7°C | 15.7°C | 78 | 8.5 | 12.913 h |
| May | 29.9°C19.9°C | 19.9°C | 103 | 11.2 | 13.614 h |
| June | 33.0°C23.1°C | 23.1°C | 69 | 9.5 | 14.014 h |
| July | 34.5°C24.1°C | 24.1°C | 50 | 6.1 | 13.814 h |
| August | 35.1°C24.7°C | 24.7°C | 50 | 5.8 | 13.213 h |
| September | 31.6°C22.0°C | 22.0°C | 77 | 8.6 | 12.412 h |
| October | 27.3°C17.3°C | 17.3°C | 83 | 7.7 | 11.511 h |
| November | 21.5°C11.7°C | 11.7°C | 67 | 7.2 | 10.711 h |
| December | 17.5°C7.8°C | 7.8°C | 63 | 7.5 | 10.310 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
January in nearby cities
- New Braunfels in JanuaryUnited States · 47 kmHigh 16.4°C · Low 6.6°C · 63 mm rain
- Austin in JanuaryUnited States · 118 kmHigh 15.9°C · Low 5.9°C · 61 mm rain
- Round Rock in JanuaryUnited States · 144 kmHigh 15.6°C · Low 5.8°C · 59 mm rain
- Killeen in JanuaryUnited States · 202 kmHigh 14.9°C · Low 4.9°C · 59 mm rain
- Corpus Christi in JanuaryUnited States · 210 kmHigh 18.9°C · Low 10.6°C · 48 mm rain
- Piedras Negras in JanuaryMexico · 213 kmHigh 19.0°C · Low 7.9°C · 25 mm rain
- Temple in JanuaryUnited States · 216 kmHigh 14.8°C · Low 5.0°C · 72 mm rain
- Ciudad Acuña in JanuaryMexico · 238 kmHigh 18.2°C · Low 7.1°C · 22 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for San Antonio) is explained once on the San Antonio year overview and on the Sources, method and limits page.