Climate and average weather in San Antonio

In San Antonio, the weather is warm, showery, and mostly clear and remarkably steady, with daytime highs holding near warm levels all year. The wettest stretch peaks around February.

Best: early April to mid December

Over the course of the year, the temperature in San Antonio typically varies from 13°C to 23°C, and is rarely below 11°C or above 25°C. October is the hottest month of the year, while July is the coldest.

Based on the travel score, the best time of year to visit San Antonio for warm-weather activities is from early April to mid December.

Hottest
Oct
23°
Coldest
Jul
13°
Wettest
Feb
63 mm
Driest
Jun
0 mm
Rain / yr
183 mm
43 wet days
Daylight
11.0–13.0 h
shortest–longest
Elevation
1,455 m
17.2°S
Clearest
Aug
16% cloud

San Antonio weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around early April to mid December.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in San Antonio, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

Temperatures in San Antonio stay fairly even through the year, without a distinct hot or cool season. The warmest month is October, with an average high of 23°C and low of 15°C; the coolest is July, with an average low of 13°C and high of 22°C.

Days typically run about 8°C warmer than nights year-round.

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan2215
Feb2215
Mar2215
Apr2315
May2314
Jun2213
Jul2213
Aug2213
Sep2314
Oct2315
Nov2315
Dec2315

Average hourly temperature in San Antonio

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on October afternoons, near 23°C, and coldest before dawn in July, near 13°C.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

San Antonio weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan22° / 15°521212.96.0
Feb22° / 15°6313.212.65.6
Mar22° / 15°4110.212.16.3
Apr23° / 15°92.111.68.2
May23° / 14°10.211.29.1
Jun22° / 13°00.1119.0
Jul22° / 13°00.211.19.0
Aug22° / 13°10.311.49.1
Sep23° / 14°10.211.99.2
Oct23° / 15°10.212.48.8
Nov23° / 15°20.612.88.5
Dec23° / 15°133.3137.6

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

San Antonio gets about 183 mm of precipitation a year. On a typical day the chance of rain is mostly dry, but that rises and falls sharply with the seasons.

The wetter season lasts 3.6 months, from around Dec 18 to Apr 7, peaking in February at about 48% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jun 17.

February is the wettest month by volume, with 63 mm over about 13 wet days; June is the driest, with 0 mm.

0%10%20%30%40%50%60%JanFebMarAprMayJunJulAugSepOctNovDecwetterdriermostly drysome rainoften wetvery wetFeb 15 · 48%Jun 17 · 0%
Rain on a day (%)Rain days
Jan3812
Feb4713
Mar3310
Apr82
May10
Jun00
Jul00
Aug10
Sep10
Oct10
Nov21
Dec113

Monthly rainfall

Over a full year, San Antonio collects about 183 mm of rain across 43 wet days — roughly 15 mm in an average month.

It doesn’t fall evenly. February is the wettest month with 63 mm, while June is the driest at just 0 mm. The three wettest months alone bring about 85% of the year’s total.

0255075JanFebMarAprMayJunJulAugSepOctNovDec5263419100111213
Rainfall (mm)Rain days
Jan5212
Feb6313
Mar4110
Apr92
May10
Jun00
Jul00
Aug10
Sep10
Oct10
Nov21
Dec133

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In San Antonio, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around April 17 and lasts for 7.1 months, ending around November 18. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 91% of the time on average.

The cloudier part of the year begins around November 19 and lasts for 4.9 months, ending around April 16. The cloudiest month is February, when it is overcast or mostly cloudy 87% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecAug 26 · 92%Feb 20 · 11%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan1882
Feb1387
Mar2278
Apr5941
May8317
Jun8713
Jul8911
Aug919
Sep8812
Oct7426
Nov6238
Dec3862

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around January 1, brings about 13 hours of light; the shortest, around June 1, only 11 hours — a swing of roughly 2 hours.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan12.95:256:21
Feb12.65:416:16
Mar12.15:505:57
Apr11.65:565:32
May11.26:045:16
Jun11.06:155:13
Jul11.16:175:21
Aug11.46:055:30
Sep11.95:415:35
Oct12.45:175:41
Nov12.85:045:54
Dec13.05:096:11

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

San Antonio averages about 15 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 1 and 26 days.

The sunnier stretch runs 6.7 months, from around Apr 20 to Nov 8. The sunniest month is August, with roughly 26 sunny days (brilliant).

The greyest month is February, down near 1 sunny days — about 95% fewer than the August peak.

051015202530JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightbrilliantAug 2726 daysFeb 201 days
Sunny daysSky
Jan2Gloomy
Feb1Gloomy
Mar3Gloomy
Apr13Mixed
May22Bright
Jun24Brilliant
Jul26Brilliant
Aug26Brilliant
Sep24Brilliant
Oct18Bright
Nov13Mixed
Dec6Gloomy

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In San Antonio, the air stays dry or comfortable essentially all year. Even in February, the muggiest month, it feels humid or worse only about 4% of the time — humidity is not something you need to plan around here.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDeccomfortabledry
Dry (%)Comfortable (%)Humid (%)
Jan52463
Feb32644
Mar43561
Apr83170
May9910
Jun10000
Jul10000
Aug10000
Sep10000
Oct10000
Nov9910
Dec88120

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Wind in San Antonio is steady company: average speeds sit near 6 km/hcalm — in every month of the year, with no meaningful windy or calm season.

0510JanFebMarAprMayJunJulAugSepOctNovDeccalmJan 1 · 7 km/hJun 9 · 6 km/h
Wind speed (km/h)Feels
Jan7calm
Feb7calm
Mar6calm
Apr6calm
May6calm
Jun6calm
Jul6calm
Aug6calm
Sep6calm
Oct6calm
Nov7calm
Dec7calm

Best time to visit San Antonio

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in San Antonio throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around mid April, San Antonio is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit San Antonio for general outdoor tourist activities is from early April to mid December, with a peak score in the first week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationSep 3 · 9.3

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan6.0good
Feb5.6good
Mar6.3good
Apr8.2ideal
May9.1ideal
Jun9.0ideal
Jul9.0ideal
Aug9.2ideal
Sep9.2ideal
Oct8.9ideal
Nov8.5ideal
Dec7.6ideal

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit San Antonio for hot-weather activities is from mid April to mid December, with a peak score in the second week of May.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationMay 9 · 7.1

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for San Antonio, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

San Antonio packs about the same all year — highs hold near 23°C. Across the year the things worth having are light clothes and sun protection.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In October, San Antonio sees daytime highs around 23°C and nights near 15°C. Pack sun protection. Worth having: light clothes.

Sea temperature near San Antonio

Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.

The sea at the nearest coast (about 51 km away) is warmest in February at about 22°C and coldest in August near 17°C.

It's comfortable for a long swim from Dec 3 to Apr 19 — about 4.5 months when the water holds above 20°C.

16°18°20°22°24°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingcomfortable to swim
Sea temperature (°C)Comfort
Jan22Refreshing
Feb22Refreshing
Mar21Refreshing
Apr20Refreshing
May19Cool
Jun18Cool
Jul17Cool
Aug17Cool
Sep17Cool
Oct18Cool
Nov19Cool
Dec21Refreshing

UV index (midday) in San Antonio by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in San Antonio peaks around February 8 at about 18 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 23 at about 9 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeFeb 8UV 18Jun 23UV 9
UV index (midday)Level
Jan18Extreme
Feb18Extreme
Mar15Extreme
Apr13Extreme
May10Extreme
Jun9Very high
Jul9Very high
Aug11Extreme
Sep13Extreme
Oct16Extreme
Nov15Extreme
Dec16Extreme

Average hourly UV index in San Antonio

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in February the burn window is concentrated in the middle of the day: about 9 hours a day reach index 3 (protection recommended), and 7.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan97.5
Feb97.5
Mar86.5
Apr86
May75
Jun6.54
Jul6.54
Aug7.55.5
Sep86
Oct8.57
Nov97
Dec97.5
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

San Antonio is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecfrost-free year round
Frost-free chance (%)Frost nights
Jan1000
Feb1000
Mar1000
Apr1000
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov1000
Dec1000

Growing degree days

Degree days (base 10°C)Frost-free shaded

Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. San Antonio banks about 3,030 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around October.

01,0002,0003,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan262
Feb236
Mar262
Apr262
May262
Jun226
Jul223
Aug242
Sep256
Oct273
Nov259
Dec268

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

San Antonio receives about 6.6 kWh/m² a day of solar energy on average — intense — with a clear seasonal swing between 5.1 and 8.3 kWh/m².

The brighter stretch of the year lasts 4.8 months, from around Aug 30 to Jan 23. The brightest month is November, averaging about 8.3 kWh/m² (intense).

The dimmest month is June, down near 5.2 kWh/m² — roughly 38% less than the November peak.

0123456789JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmoderatebrightintenseNov 238.3 kWhJun 245.1 kWh
Solar energy (kWh/m²)Level
Jan6.7Intense
Feb6.3Intense
Mar6.2Intense
Apr6.2Intense
May5.7Bright
Jun5.1Bright
Jul5.3Bright
Aug6.1Intense
Sep7.1Intense
Oct8.0Intense
Nov8.3Intense
Dec7.8Intense

Where is San Antonio?

San Antonio sits at 17.2°S, 70.9°W, 1,455 m above sea level, in Peru. The nearest listed city is Moquegua, 2.0 km away.

TacnaSelva AlegreMollendo

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 significant variations in elevation — a maximum elevation change of 466 m around an average of 1,486 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,183 m; within 80 km, extreme variations in elevation — a maximum elevation change of 5,786 m.

The land around San Antonio is covered by bare terrain (64%) within 3 km, bare terrain (90%) within 16 km, and bare terrain (76%) within 80 km.

3 km
466 m
16 km
2,183 m
80 km
5,786 m
shrubsgrasslandcroplandartificial surfacesbare terrainwater
Nearby: Moquegua 2.0 km · Ilo 64 km · Ciudad Satelite 108 km · Jacobo Hunter 109 km · Arequipa 112 km · Tacna 114 km · Selva Alegre 114 km · Mollendo 118 km

Peru travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / B / C
220 V · 60 Hz
Prices
≈ 51% of US
price level, 2025
GDP per capita
$9,684
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
49%
of population, 2024
Homicide rate
8.6
per 100k, 2021
Road deaths
13.6
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Moderate
EF EPI 519
Religion
Catholic 76%Evangelical Christian 16%no religion 5%other religions 3%

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 (-17.2172°, -70.9259°, elevation 1,455 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).