San Marcos in Fall
In fall (September, October and November), San Marcos sees average daytime highs around 79°F and overnight lows near 60°F, with 9.0 in of rain over about 23 wet days across the season. It is the 2nd-warmest season and the 2nd-wettest season.
Over the season highs ease from about 91°F in early September to 66°F by late November. The sky is clear or mostly clear about 48% of the time across fall, and the air most often feels dry.
Fall is San Marcos's 2nd-best season to visit on our travel score. For the whole year in context, see San Marcos's year-round climate.
- Avg daytime high
- 79°F
- 2nd-warmest season
- Avg overnight low
- 60°F
- Rainfall
- 9.0 in
- 23 wet days
- Avg wind
- 7 mph
- Travel score
- 6.3
- 2nd-best season
- Months
- Sep · Oct · Nov
Temperature in San Marcos in Fall
Over the season highs ease from about 91°F in early September to 66°F by late November.
A typical fall day in San Marcos reaches about 79°F and drops to 60°F overnight. The warmest of the three months is September, the coolest November.
How fall really feels in San Marcos
Once humidity and wind are folded in, fall brings about 18 days that feel above 90°F and 0 that feel at or below 32°F.
The story in fall is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
San Marcos weather by month
How the three fall months (September, October and November) compare with the rest of the year — the season's months are highlighted.
| 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 Fall
The sky is clear or mostly clear about 48% of the time across fall.
Chance of precipitation in Fall
San Marcos gets around 9.0 in of rain over 23 wet days across fall. The line is the day-by-day chance of measurable precipitation.
Humidity in Fall
Most of fall feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Fall
Winds average 7 mph across fall.
Sunrise & sunset in Fall
Daylight runs from about 12 h 36 min in early September to 10 h 12 min by late November. The lit band spans sunrise to sunset each day.
Solar energy in Fall
Average shortwave solar energy reaching the ground each day across fall, about 4.1 kWh/m².
Is fall a good time to visit San Marcos?
Our two travel scores rate fall for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
fall is a reasonable time to visit San Marcos for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for San Marcos in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, San Marcos sees daytime highs around 79°F and nights near 60°F. Pack light clothes. Worth having: rain gear and sun protection. About 23 days see rain.
UV index in San Marcos in Fall
Clear-sky midday UV across fall averages around 7 — enough to warrant sun protection. 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 Fall
Average fine-particle pollution (PM2.5) through the year — so you can see where fall 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.