San Antonio in Fall
In fall (March, April and May), San Antonio sees average daytime highs around 18°C and overnight lows near 11°C, with 82 mm of rain over about 8 wet days across the season. It is the 2nd-warmest season and the 2nd-wettest season.
Over the season highs ease from about 20°C in early March to 15°C by late May. The sky is clear or mostly clear about 59% of the time across fall, and the air most often feels dry.
Fall is San Antonio's 2nd-best season to visit on our travel score. For the whole year in context, see San Antonio's year-round climate.
- Avg daytime high
- 18°C
- 2nd-warmest season
- Avg overnight low
- 11°C
- Rainfall
- 82 mm
- 8 wet days
- Avg wind
- 9 km/h
- Travel score
- 7.0
- 2nd-best season
- Months
- Mar · Apr · May
Temperature in San Antonio in Fall
Over the season highs ease from about 20°C in early March to 15°C by late May.
A typical fall day in San Antonio reaches about 18°C and drops to 11°C overnight. The warmest of the three months is March, the coolest May.
San Antonio weather by month
How the three fall months (March, April and May) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 21° / 14° | 0 | 0.1 | 14 | 8.8 |
| Feb | 21° / 14° | 2 | 0.3 | 13.2 | 8.7 |
| Mar | 20° / 12° | 4 | 0.7 | 12.3 | 8.4 |
| Apr | 18° / 10° | 18 | 2.2 | 11.2 | 7.2 |
| May | 16° / 9° | 61 | 4.7 | 10.3 | 5.5 |
| Jun | 14° / 8° | 122 | 7 | 9.8 | 4.3 |
| Jul | 13° / 7° | 67 | 5.5 | 10 | 4.2 |
| Aug | 14° / 7° | 59 | 5.1 | 10.8 | 4.6 |
| Sep | 15° / 8° | 28 | 3 | 11.8 | 5.5 |
| Oct | 17° / 10° | 14 | 1.8 | 12.8 | 6.7 |
| Nov | 18° / 11° | 4 | 0.7 | 13.7 | 7.9 |
| Dec | 20° / 12° | 3 | 0.4 | 14.2 | 8.4 |
Cloud cover in Fall
The sky is clear or mostly clear about 59% of the time across fall.
Chance of precipitation in Fall
San Antonio gets around 82 mm of rain over 8 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 9 km/h across fall.
Sunrise & sunset in Fall
Daylight runs from about 12 h 48 min in early March to 10 hours by late May. 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 4.7 kWh/m².
Is fall a good time to visit San Antonio?
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 one of the better times to visit San Antonio for general sightseeing.
What to pack for San Antonio in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, San Antonio sees daytime highs around 18°C and nights near 11°C. Pack sun protection. Worth having: a warm layer. About 8 days see rain.
Sea temperature near San Antonio in Fall
The nearest coast averages about 15°C across fall — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea offshore is warmest in February at about 16°C and coldest in August near 12°C.
The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 16 | 16 | 16 | 14 | 14 | 13 | 13 | 12 | 12 | 13 | 13 | 15 |
| Comfort | Cool | Cool | Cool | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 16 | Cool |
| Feb | 16 | Cool |
| Mar | 16 | Cool |
| Apr | 14 | Bracing |
| May | 14 | Bracing |
| Jun | 13 | Bracing |
| Jul | 13 | Bracing |
| Aug | 12 | Bracing |
| Sep | 12 | Bracing |
| Oct | 13 | Bracing |
| Nov | 13 | Bracing |
| Dec | 15 | Bracing |
UV index in San Antonio in Fall
Clear-sky midday UV across fall averages around 6 — 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 Antonio peaks around January 17 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 19 at about 3 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 14 | 12 | 10 | 5 | 3 | 3 | 3 | 4 | 6 | 9 | 11 | 12 |
| Level | Extreme | Extreme | Very high | High | Moderate | Moderate | Moderate | Moderate | High | Very high | Extreme | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 14 | Extreme |
| Feb | 12 | Extreme |
| Mar | 10 | Very high |
| Apr | 5 | High |
| May | 3 | Moderate |
| Jun | 3 | Moderate |
| Jul | 3 | Moderate |
| Aug | 4 | Moderate |
| Sep | 6 | High |
| Oct | 9 | Very high |
| Nov | 11 | Extreme |
| Dec | 12 | Extreme |
Air quality in San Antonio 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 Antonio is worst in July — around 88 µg/m³ PM2.5 (unhealthy), about 2.5× the cleanest month (February, 35 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) | 45 | 35 | 40 | 58 | 83 | 85 | 88 | 77 | 64 | 45 | 37 | 38 |
| Level | Poor | Moderate | Poor | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Poor | Poor | Poor |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 45 | Poor |
| Feb | 35 | Moderate |
| Mar | 40 | Poor |
| Apr | 58 | Unhealthy |
| May | 83 | Unhealthy |
| Jun | 85 | Unhealthy |
| Jul | 88 | Unhealthy |
| Aug | 77 | Unhealthy |
| Sep | 64 | Unhealthy |
| Oct | 45 | Poor |
| Nov | 37 | Poor |
| Dec | 38 | Poor |
Where is San Antonio?
San Antonio sits at 33.6°S, 71.6°W, 39 m above sea level, in Chile. The nearest listed city is Cartagena, 5.0 km away.
Topography around San Antonio
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Antonio.
Within 3 km, the terrain around San Antonio has only modest variations in elevation — a maximum elevation change of 212 m around an average of 54 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 488 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,259 m.
The land around San Antonio is covered by artificial surfaces (38%) and water (23%) within 3 km, water (40%) and grassland (24%) within 16 km, and water (29%) and grassland (22%) within 80 km.
Chile travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type C / F / L
- 220 V · 50 Hz
- Prices
- ≈ 48% of US
- price level, 2025
- GDP per capita
- $17,995
- 2025
- Happiness
- 6.3 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 6.3
- per 100k, 2023
- Road deaths
- 14.9
- per 100k/yr, 2019
- Income group
- High
- World Bank
- English
- Moderate
- EF EPI 517
- 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 Antonio (-33.5947°, -71.6075°, elevation 39 m), 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.