San Marcos weather in January: San Marcos, Texas: normal highs, lows, rain and records for January
San Marcos in January has a normal high of 62°F and a normal low of 39°F, a daily mean of 51°F, rising from 62°F on the 1st to 64°F by the 31st. Measurable precipitation falls on 7 days in a normal January, 2.41 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 17°C and low of 4°C, 61 mm of precipitation in January.
- NOAA stationSan Marcos
- Station IDUSC00417983
- Location29.88°N 97.95°W
- Elevation665 ft (203 m)
- Population74,316
- Jan 62° 39°
- Feb 67° 42°
- Mar 73° 50°
- Apr 80° 56°
- May 86° 65°
- Jun 92° 72°
- Jul 96° 73°
- Aug 97° 74°
- Sep 91° 69°
- Oct 82° 58°
- Nov 72° 48°
- Dec 64° 41°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is San Marcos in January?
The normal high is 62°F and the normal low 39°F, for a daily mean of 50.6°F. January is 1.6°F cooler than December and 3.9°F cooler than February. January is the 12th warmest month of the year in San Marcos and the 9th wettest. Across the month the normal high rises 2°F, from 62°F on January 1 to 64°F on January 31. From one year to the next January's mean temperature typically moves about 3.3°F either way (NOAA's standard deviation), so roughly two Januarys in three average between 47°F and 54°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 25%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| January 1 | 62°F | 39°F | 25% | 13% |
| January 8 | 62°F | 39°F | 24% | 13% |
| January 15 | 62°F | 39°F | 24% | 13% |
| January 22 | 63°F | 39°F | 24% | 13% |
| January 31 | 64°F | 40°F | 24% | 13% |
Every day of January: normal high, low and chance of precipitation (warmest afternoon January 31, coldest night January 5)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| January 1 | 62°F | 39°F | 25% | 13% | 10 h 20 min |
| January 2 | 62°F | 39°F | 25% | 13% | 10 h 20 min |
| January 3 | 62°F | 39°F | 25% | 13% | 10 h 20 min |
| January 4 | 62°F | 39°F | 25% | 13% | 10 h 20 min |
| January 5 | 62°F | 39°F | 25% | 13% | 10 h 20 min |
| January 6 | 62°F | 39°F | 24% | 13% | 10 h 20 min |
| January 7 | 62°F | 39°F | 24% | 13% | 10 h 20 min |
| January 8 | 62°F | 39°F | 24% | 13% | 10 h 20 min |
| January 9 | 62°F | 39°F | 24% | 13% | 10 h 20 min |
| January 10 | 62°F | 39°F | 24% | 13% | 10 h 20 min |
| January 11 | 62°F | 39°F | 24% | 13% | 10 h 20 min |
| January 12 | 62°F | 39°F | 24% | 13% | 10 h 20 min |
| January 13 | 62°F | 39°F | 24% | 13% | 10 h 20 min |
| January 14 | 62°F | 39°F | 24% | 13% | 10 h 20 min |
| January 15 | 62°F | 39°F | 24% | 13% | 10 h 30 min |
| January 16 | 62°F | 39°F | 24% | 13% | 10 h 30 min |
| January 17 | 62°F | 39°F | 24% | 13% | 10 h 30 min |
| January 18 | 62°F | 39°F | 24% | 13% | 10 h 30 min |
| January 19 | 62°F | 39°F | 24% | 13% | 10 h 30 min |
| January 20 | 62°F | 39°F | 24% | 13% | 10 h 30 min |
| January 21 | 63°F | 39°F | 24% | 13% | 10 h 30 min |
| January 22 | 63°F | 39°F | 24% | 13% | 10 h 30 min |
| January 23 | 63°F | 39°F | 24% | 13% | 10 h 30 min |
| January 24 | 63°F | 39°F | 24% | 13% | 10 h 30 min |
| January 25 | 63°F | 39°F | 24% | 13% | 10 h 40 min |
| January 26 | 63°F | 39°F | 24% | 13% | 10 h 40 min |
| January 27 | 63°F | 40°F | 24% | 13% | 10 h 40 min |
| January 28 | 64°F | 40°F | 24% | 13% | 10 h 40 min |
| January 29 | 64°F | 40°F | 24% | 13% | 10 h 40 min |
| January 30 | 64°F | 40°F | 24% | 13% | 10 h 40 min |
| January 31 | 64°F | 40°F | 24% | 13% | 10 h 40 min |
- Normal high
- 62°FJanuary average
- Normal low
- 39°FJanuary average
- Precipitation
- 2.41 inmonth total
- Days with precipitation
- 70.01 inch or more
- Nights at 32°F or colder
- 7
- Daylight
- 10 h 20 min to 10 h 40 minJanuary 1 to January 31
- Days at 70°F or more
- 10
- Days at 80°F or more
- 1
- Sunshine
- 72%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00417983; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in San Marcos in January?
On a given January day the chance of 0.01 inch or more is 24% on average, highest around January 1 (25%). In all, 2.41 in falls on 7 days of a normal January, 1 of them with an inch or more.
In a normal January in San Marcos, 7 nights fall to freezing.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00417983.
What are the records for January in San Marcos?
The warmest January temperature on this station's record (since 1895) is 89°F, on January 25, 1918; the coldest is −2°F, on January 31, 1949. The wettest January brought 8.20 in (1968); the snowiest, 6.0 inches (1926).
The January mean against the 1991-2020 normal of 50.6°F: 2021 50.8°F (+0.2), 2022 47.9°F (−2.7), 2023 54.3°F (+3.7), 2024 46.1°F (−4.5), 2025 45.3°F (−5.3), 2026 52.9°F (+2.3). 3 of 6 ran warmer than normal.
| January | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 50.8°F | +0.2°F | 1.34 in |
| 2022 | 47.9°F | −2.7°F | 1.03 in |
| 2023 | 54.3°F | +3.7°F | 1.29 in |
| 2024 | 46.1°F | −4.5°F | 7.95 in |
| 2025 | 45.3°F | −5.3°F | 1.73 in |
| 2026 | 52.9°F | +2.3°F | 0.95 in |
Source: records: ACIS, station USC00417983; recent months: ACIS, station USC00417983. Records and recent months use complete months only.
How does January in San Marcos compare across Texas?
Across the 321 places PlainClimate covers in Texas, January normal highs run from 49°F in Follett to 73°F in McAllen; San Marcos's is 62°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.