San Marcos weather in August
In August, San Marcos sees average daytime highs of 94°F and overnight lows near 74°F, with 2.4 in of rain across 6.4 wet days and about 13.1 hours of daylight. It is the 1st-warmest and 11th-wettest month of the year here.
Day-to-day highs hold fairly steady near 94°F through the month. The sky is clear or mostly clear about 52% of the time in August, and the air most often feels muggy.
Daylight stretches from about 13 h 30 min at the start of August to 12 h 42 min by month's end. Set against the rest of the year, August is San Marcos's 2nd-clearest and 11th-windiest month. For the whole year in context, see San Marcos's year-round climate.
- Daytime high
- 94°
- 1st warmest
- Overnight low
- 74°
- 12th coldest
- Rainfall
- 2.4 in
- 6.4 wet days
- Daylight
- 13 h 06 min
- 6:03 AM – 7:08 PM
- Cloud cover
- 45%
- 2nd clearest
- Wind
- 6 mph
- 11th windiest
- Solar energy
- 6.27 kWh/m²
- Travel score
- 3.0
- out of 10
San Marcos is city in and county seat of Hays County, Texas, United States, that extends into Caldwell and Guadalupe counties.
- Density
- 684/km²
- people per km²
- Founded
- 1808
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in August
Day-to-day highs hold fairly steady near 94°F through the month.
A typical August day in San Marcos reaches about 94°F in the afternoon and slips back to 74°F overnight — a 20°F spread between the day's warmth and the night's chill. On most days the high lands between 88°F and 100°F. Set against its neighbours, August runs on par with July and about 6°F warmer than September.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 95 | 95 | 95 | 95 | 95 | 95 | 95 | 95 | 95 | 95 | 95 | 95 | 95 | 95 | 95 | 95 | 94 | 94 | 94 | 94 | 94 | 94 | 94 | 94 | 93 | 93 | 93 | 93 | 92 | 92 | 92 |
| Avg low (°F) | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 74 | 73 | 73 | 73 | 73 | 73 | 73 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 95 | 74 |
| 2 | 95 | 74 |
| 3 | 95 | 74 |
| 4 | 95 | 74 |
| 5 | 95 | 74 |
| 6 | 95 | 74 |
| 7 | 95 | 74 |
| 8 | 95 | 74 |
| 9 | 95 | 74 |
| 10 | 95 | 74 |
| 11 | 95 | 74 |
| 12 | 95 | 74 |
| 13 | 95 | 74 |
| 14 | 95 | 74 |
| 15 | 95 | 74 |
| 16 | 95 | 74 |
| 17 | 94 | 74 |
| 18 | 94 | 74 |
| 19 | 94 | 74 |
| 20 | 94 | 74 |
| 21 | 94 | 74 |
| 22 | 94 | 74 |
| 23 | 94 | 74 |
| 24 | 94 | 74 |
| 25 | 93 | 74 |
| 26 | 93 | 73 |
| 27 | 93 | 73 |
| 28 | 93 | 73 |
| 29 | 92 | 73 |
| 30 | 92 | 73 |
| 31 | 92 | 73 |
How August really feels in San Marcos
Once humidity and wind are folded in, August averages 31 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.
The story in August is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
San Marcos weather by month
How August compares with the rest of the year at a glance. August is the 1st-warmest and 11th-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 61° / 42° | 2.5 | 7.4 | 10.3 | 5.4 |
| Feb | 65° / 46° | 2.4 | 7.6 | 10.9 | 6.2 |
| Mar | 71° / 52° | 3.0 | 9.4 | 11.8 | 6.8 |
| Apr | 78° / 59° | 3.3 | 9 | 12.7 | 6.9 |
| May | 85° / 66° | 4.5 | 11.4 | 13.5 | 5.3 |
| Jun | 90° / 72° | 3.2 | 9.8 | 13.9 | 3.9 |
| Jul | 94° / 74° | 1.8 | 6.4 | 13.7 | 3.2 |
| Aug | 94° / 74° | 2.4 | 6.4 | 13.1 | 3.0 |
| Sep | 88° / 69° | 3.0 | 8.2 | 12.2 | 4.7 |
| Oct | 80° / 60° | 3.2 | 7.5 | 11.3 | 7.1 |
| Nov | 69° / 50° | 2.8 | 7 | 10.5 | 7.0 |
| Dec | 62° / 43° | 2.8 | 7.9 | 10.1 | 5.7 |
Cloud cover in August
The sky is clear or mostly clear about 52% of the time in August.
Beyond those clear spells, partly cloudy skies cover about 19% of August, with mostly cloudy or overcast conditions the remaining 29%.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 71 | 71 | 72 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 73 | 72 | 72 | 71 | 71 | 70 | 70 | 71 | 70 | 70 | 70 | 70 | 70 | 70 | 69 | 69 | 69 | 69 | 69 | 68 | 68 |
| Cloudier (%) | 29 | 29 | 28 | 27 | 27 | 27 | 27 | 27 | 27 | 27 | 27 | 28 | 28 | 29 | 29 | 30 | 30 | 29 | 30 | 30 | 30 | 30 | 30 | 30 | 31 | 31 | 31 | 31 | 31 | 32 | 32 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 71 | 29 |
| 2 | 71 | 29 |
| 3 | 72 | 28 |
| 4 | 73 | 27 |
| 5 | 73 | 27 |
| 6 | 73 | 27 |
| 7 | 73 | 27 |
| 8 | 73 | 27 |
| 9 | 73 | 27 |
| 10 | 73 | 27 |
| 11 | 73 | 27 |
| 12 | 72 | 28 |
| 13 | 72 | 28 |
| 14 | 71 | 29 |
| 15 | 71 | 29 |
| 16 | 70 | 30 |
| 17 | 70 | 30 |
| 18 | 71 | 29 |
| 19 | 70 | 30 |
| 20 | 70 | 30 |
| 21 | 70 | 30 |
| 22 | 70 | 30 |
| 23 | 70 | 30 |
| 24 | 70 | 30 |
| 25 | 69 | 31 |
| 26 | 69 | 31 |
| 27 | 69 | 31 |
| 28 | 69 | 31 |
| 29 | 69 | 31 |
| 30 | 68 | 32 |
| 31 | 68 | 32 |
Chance of precipitation in August
San Marcos gets around 2.4 in of rain over 6.4 wet days in August. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 21% and peaks near 26% on the wettest days. The odds climb toward the end of the month.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 15 | 15 | 15 | 16 | 16 | 16 | 17 | 17 | 18 | 18 | 19 | 19 | 20 | 20 | 21 | 22 | 22 | 22 | 23 | 23 | 23 | 23 | 24 | 24 | 24 | 24 | 25 | 25 | 25 | 26 | 26 |
| Rain chance (%) | |
|---|---|
| 1 | 15 |
| 2 | 15 |
| 3 | 15 |
| 4 | 16 |
| 5 | 16 |
| 6 | 16 |
| 7 | 17 |
| 8 | 17 |
| 9 | 18 |
| 10 | 18 |
| 11 | 19 |
| 12 | 19 |
| 13 | 20 |
| 14 | 20 |
| 15 | 21 |
| 16 | 22 |
| 17 | 22 |
| 18 | 22 |
| 19 | 23 |
| 20 | 23 |
| 21 | 23 |
| 22 | 23 |
| 23 | 24 |
| 24 | 24 |
| 25 | 24 |
| 26 | 24 |
| 27 | 25 |
| 28 | 25 |
| 29 | 25 |
| 30 | 26 |
| 31 | 26 |
Humidity in August
Most of August feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, August lands in the muggy band about 51% of days. Sticky, muggy-or-worse air turns up on roughly 88% of them.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 2 |
| Comfortable (%) | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 4 | 4 | 5 | 5 | 5 |
| Humid (%) | 8 | 8 | 8 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 8 | 8 | 9 | 9 | 10 | 10 | 11 | 11 | 11 | 12 | 12 | 13 | 13 | 13 | 14 | 14 | 14 |
| Muggy (%) | 55 | 56 | 56 | 58 | 59 | 59 | 59 | 59 | 59 | 58 | 58 | 57 | 57 | 56 | 55 | 53 | 52 | 51 | 49 | 48 | 46 | 45 | 44 | 43 | 43 | 42 | 42 | 41 | 40 | 40 | 39 |
| Oppressive (%) | 36 | 35 | 35 | 34 | 33 | 33 | 33 | 33 | 33 | 33 | 33 | 34 | 34 | 35 | 35 | 36 | 36 | 37 | 38 | 38 | 39 | 40 | 40 | 40 | 40 | 40 | 40 | 40 | 39 | 39 | 39 |
| Miserable (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| 1 | 0 | 1 | 8 | 55 | 36 | 0 |
| 2 | 0 | 1 | 8 | 56 | 35 | 0 |
| 3 | 0 | 1 | 8 | 56 | 35 | 0 |
| 4 | 0 | 1 | 7 | 58 | 34 | 0 |
| 5 | 0 | 1 | 7 | 59 | 33 | 0 |
| 6 | 0 | 1 | 7 | 59 | 33 | 0 |
| 7 | 0 | 1 | 7 | 59 | 33 | 0 |
| 8 | 0 | 1 | 7 | 59 | 33 | 0 |
| 9 | 0 | 1 | 7 | 59 | 33 | 0 |
| 10 | 0 | 2 | 7 | 58 | 33 | 0 |
| 11 | 0 | 2 | 7 | 58 | 33 | 0 |
| 12 | 0 | 2 | 7 | 57 | 34 | 0 |
| 13 | 0 | 2 | 7 | 57 | 34 | 0 |
| 14 | 0 | 2 | 7 | 56 | 35 | 0 |
| 15 | 0 | 2 | 8 | 55 | 35 | 0 |
| 16 | 0 | 2 | 8 | 53 | 36 | 1 |
| 17 | 0 | 2 | 9 | 52 | 36 | 1 |
| 18 | 0 | 2 | 9 | 51 | 37 | 1 |
| 19 | 0 | 3 | 10 | 49 | 38 | 1 |
| 20 | 0 | 3 | 10 | 48 | 38 | 1 |
| 21 | 0 | 3 | 11 | 46 | 39 | 1 |
| 22 | 0 | 3 | 11 | 45 | 40 | 1 |
| 23 | 0 | 3 | 11 | 44 | 40 | 1 |
| 24 | 0 | 4 | 12 | 43 | 40 | 1 |
| 25 | 0 | 4 | 12 | 43 | 40 | 1 |
| 26 | 0 | 4 | 13 | 42 | 40 | 1 |
| 27 | 1 | 4 | 13 | 42 | 40 | 1 |
| 28 | 1 | 4 | 13 | 41 | 40 | 1 |
| 29 | 1 | 5 | 14 | 40 | 39 | 1 |
| 30 | 1 | 5 | 14 | 40 | 39 | 1 |
| 31 | 2 | 5 | 14 | 39 | 39 | 1 |
Wind in August
Winds average 6 mph in August.
Across August, daily wind ranges from about 6 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (mph) | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 7 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 | 6 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (mph) | Feels | |
|---|---|---|
| 1 | 7 | calm |
| 2 | 7 | calm |
| 3 | 7 | calm |
| 4 | 7 | calm |
| 5 | 7 | calm |
| 6 | 7 | calm |
| 7 | 7 | calm |
| 8 | 7 | calm |
| 9 | 7 | calm |
| 10 | 7 | calm |
| 11 | 7 | calm |
| 12 | 7 | calm |
| 13 | 7 | calm |
| 14 | 7 | calm |
| 15 | 7 | calm |
| 16 | 7 | calm |
| 17 | 7 | calm |
| 18 | 7 | calm |
| 19 | 6 | calm |
| 20 | 6 | calm |
| 21 | 6 | calm |
| 22 | 6 | calm |
| 23 | 6 | calm |
| 24 | 6 | calm |
| 25 | 6 | calm |
| 26 | 6 | calm |
| 27 | 6 | calm |
| 28 | 6 | calm |
| 29 | 6 | calm |
| 30 | 6 | calm |
| 31 | 6 | calm |
Sunrise & sunset in August
Daylight runs from about 13 h 30 min at the start of August to 12 h 42 min by month's end. The lit band spans sunrise to sunset each day.
Days shrink by about 48 minutes over August. Sunrise moves from 5:54 AM to 6:12 AM, and sunset from 7:21 PM to 6:52 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 13.5 | 13.4 | 13.4 | 13.4 | 13.4 | 13.3 | 13.3 | 13.3 | 13.3 | 13.2 | 13.2 | 13.2 | 13.2 | 13.1 | 13.1 | 13.1 | 13.1 | 13.0 | 13.0 | 13.0 | 13.0 | 12.9 | 12.9 | 12.9 | 12.8 | 12.8 | 12.8 | 12.8 | 12.7 | 12.7 | 12.7 |
| Sunrise (AM) | 5:54 | 5:55 | 5:55 | 5:56 | 5:57 | 5:57 | 5:58 | 5:58 | 5:59 | 6:00 | 6:00 | 6:01 | 6:01 | 6:02 | 6:03 | 6:03 | 6:04 | 6:04 | 6:05 | 6:06 | 6:06 | 6:07 | 6:07 | 6:08 | 6:09 | 6:09 | 6:10 | 6:10 | 6:11 | 6:11 | 6:12 |
| Sunset (PM) | 7:21 | 7:21 | 7:20 | 7:19 | 7:18 | 7:18 | 7:17 | 7:16 | 7:15 | 7:14 | 7:13 | 7:12 | 7:11 | 7:10 | 7:09 | 7:08 | 7:07 | 7:06 | 7:05 | 7:04 | 7:03 | 7:02 | 7:01 | 7:00 | 6:59 | 6:58 | 6:56 | 6:55 | 6:54 | 6:53 | 6:52 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 13.5 | 5:54 | 7:21 |
| 2 | 13.4 | 5:55 | 7:21 |
| 3 | 13.4 | 5:55 | 7:20 |
| 4 | 13.4 | 5:56 | 7:19 |
| 5 | 13.4 | 5:57 | 7:18 |
| 6 | 13.3 | 5:57 | 7:18 |
| 7 | 13.3 | 5:58 | 7:17 |
| 8 | 13.3 | 5:58 | 7:16 |
| 9 | 13.3 | 5:59 | 7:15 |
| 10 | 13.2 | 6:00 | 7:14 |
| 11 | 13.2 | 6:00 | 7:13 |
| 12 | 13.2 | 6:01 | 7:12 |
| 13 | 13.2 | 6:01 | 7:11 |
| 14 | 13.1 | 6:02 | 7:10 |
| 15 | 13.1 | 6:03 | 7:09 |
| 16 | 13.1 | 6:03 | 7:08 |
| 17 | 13.1 | 6:04 | 7:07 |
| 18 | 13.0 | 6:04 | 7:06 |
| 19 | 13.0 | 6:05 | 7:05 |
| 20 | 13.0 | 6:06 | 7:04 |
| 21 | 13.0 | 6:06 | 7:03 |
| 22 | 12.9 | 6:07 | 7:02 |
| 23 | 12.9 | 6:07 | 7:01 |
| 24 | 12.9 | 6:08 | 7:00 |
| 25 | 12.8 | 6:09 | 6:59 |
| 26 | 12.8 | 6:09 | 6:58 |
| 27 | 12.8 | 6:10 | 6:56 |
| 28 | 12.8 | 6:10 | 6:55 |
| 29 | 12.7 | 6:11 | 6:54 |
| 30 | 12.7 | 6:11 | 6:53 |
| 31 | 12.7 | 6:12 | 6:52 |
Solar energy in August
Average shortwave solar energy reaching the ground each day in August, about 6.27 kWh/m².
For context, solar energy here swings from a low near 2.69 kWh/m² to a high of 6.69 kWh/m² in July across the year — August's 6.27 kWh/m² sits near the top of that range.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 6.7 | 6.7 | 6.7 | 6.7 | 6.6 | 6.6 | 6.6 | 6.6 | 6.5 | 6.5 | 6.5 | 6.4 | 6.4 | 6.3 | 6.3 | 6.3 | 6.2 | 6.2 | 6.1 | 6.1 | 6.1 | 6.0 | 6.0 | 6.0 | 5.9 | 5.9 | 5.8 | 5.8 | 5.8 | 5.7 | 5.7 |
| Level | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 6.7 | Intense |
| 2 | 6.7 | Intense |
| 3 | 6.7 | Intense |
| 4 | 6.7 | Intense |
| 5 | 6.6 | Intense |
| 6 | 6.6 | Intense |
| 7 | 6.6 | Intense |
| 8 | 6.6 | Intense |
| 9 | 6.5 | Intense |
| 10 | 6.5 | Intense |
| 11 | 6.5 | Intense |
| 12 | 6.4 | Intense |
| 13 | 6.4 | Intense |
| 14 | 6.3 | Intense |
| 15 | 6.3 | Intense |
| 16 | 6.3 | Intense |
| 17 | 6.2 | Intense |
| 18 | 6.2 | Intense |
| 19 | 6.1 | Intense |
| 20 | 6.1 | Intense |
| 21 | 6.1 | Intense |
| 22 | 6.0 | Intense |
| 23 | 6.0 | Bright |
| 24 | 6.0 | Bright |
| 25 | 5.9 | Bright |
| 26 | 5.9 | Bright |
| 27 | 5.8 | Bright |
| 28 | 5.8 | Bright |
| 29 | 5.8 | Bright |
| 30 | 5.7 | Bright |
| 31 | 5.7 | Bright |
Is August a good time to visit San Marcos?
Our two travel scores rate August for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
August is a weaker month for outdoor sightseeing in San Marcos. The water and warmth also suit a beach or pool day.
What to pack for San Marcos in August
From August's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In August, San Marcos sees daytime highs around 94°F and nights near 74°F. Pack light clothes and sun protection. About 6 days see rain.
UV index in San Marcos in August
Clear-sky midday UV in August peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in San Marcos peaks around August 11 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 4 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 4 | 6 | 7 | 10 | 10 | 10 | 10 | 11 | 9 | 6 | 5 | 4 |
| Level | Moderate | High | High | Very high | Extreme | Extreme | Extreme | Extreme | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 4 | Moderate |
| Feb | 6 | High |
| Mar | 7 | High |
| Apr | 10 | Very high |
| May | 10 | Extreme |
| Jun | 10 | Extreme |
| Jul | 10 | Extreme |
| Aug | 11 | Extreme |
| Sep | 9 | Very high |
| Oct | 6 | High |
| Nov | 5 | Moderate |
| Dec | 4 | Moderate |
Air quality in San Marcos in August
Average fine-particle pollution (PM2.5) through the year — so you can see where August falls, not just the annual average.
Air quality in San Marcos is worst in July — around 17 µg/m³ PM2.5 (moderate), about 2.9× the cleanest month (December, 6 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 6 | 7 | 8 | 9 | 14 | 14 | 17 | 12 | 10 | 6 | 6 | 6 |
| Level | Good | Good | Good | Good | Moderate | Moderate | Moderate | Good | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 6 | Good |
| Feb | 7 | Good |
| Mar | 8 | Good |
| Apr | 9 | Good |
| May | 14 | Moderate |
| Jun | 14 | Moderate |
| Jul | 17 | Moderate |
| Aug | 12 | Good |
| Sep | 10 | Good |
| Oct | 6 | Good |
| Nov | 6 | Good |
| Dec | 6 | Good |
Where is San Marcos?
San Marcos sits at 29.9°N, 97.9°W, 617 ft above sea level, in United States. The nearest listed city is Kyle, 8.1 mi away.
Topography around San Marcos
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of San Marcos.
Within 2 miles, the terrain around San Marcos has only modest variations in elevation — a maximum elevation change of 289 ft around an average of 643 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 751 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,814 ft.
The land around San Marcos is covered by trees (42%), artificial surfaces (31%) and grassland (23%) within 2 miles, trees (41%) and grassland (39%) within 10 miles, and trees (48%) and grassland (42%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for San Marcos (29.8833°, -97.9414°, elevation 617 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).