San Antonio weather in December

In December, San Antonio sees average daytime highs of 64°F and overnight lows near 44°F, with 2.5 in of rain across 7.5 wet days and about 10.1 hours of daylight. It is the 11th-warmest and 8th-wettest month of the year here.

Highs ease over the month, from about 66°F in the first days to 62°F by the end. The sky is clear or mostly clear about 40% of the time in December, and the air most often feels dry.

Daylight stretches from about 10 h 18 min at the start of December to 10 h 06 min by month's end. Set against the rest of the year, December is San Antonio's 9th-clearest and 8th-windiest month. For the whole year in context, see San Antonio's year-round climate.

Daytime high
64°
11th warmest
Overnight low
44°
2nd coldest
Rainfall
2.5 in
7.5 wet days
Daylight
10 h 06 min
7:26 AM – 5:34 PM
Cloud cover
55%
9th clearest
Wind
7 mph
8th windiest
Solar energy
2.72 kWh/m²
Travel score
6.1
out of 10

San Antonio is city in Bexar, Comal, and Medina counties in Texas, United States; seat of Bexar County.

Density
1,263/km²
people per km²
Founded
1718

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 66°F in the first days to 62°F by the end.

A typical December day in San Antonio reaches about 64°F in the afternoon and slips back to 44°F overnight — a 20°F spread between the day's warmth and the night's chill. On most days the high lands between 51°F and 75°F. Set against its neighbours, December runs about 7°F cooler than November and about 1°F warmer than January.

20°40°60°80°151015202531
Avg high (°F)Avg low (°F)
16747
26646
36646
46646
56546
66546
76545
86545
96545
106445
116445
126444
136444
146444
156444
166444
176344
186344
196344
206343
216343
226343
236243
246243
256243
266243
276243
286243
296243
306242
316242

How December really feels in San Antonio

Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

December sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

San Antonio weather by month

How December compares with the rest of the year at a glance. December is the 11th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan62° / 43°2.27.210.35.8
Feb67° / 46°2.37.410.96.5
Mar73° / 53°3.19.211.86.9
Apr80° / 59°3.18.512.76.8
May86° / 67°4.111.213.55.0
Jun91° / 73°2.79.513.83.6
Jul94° / 74°2.06.213.73.1
Aug95° / 74°1.95.813.12.8
Sep89° / 70°3.08.612.24.3
Oct81° / 61°3.37.711.36.8
Nov71° / 51°2.67.210.57.1
Dec64° / 44°2.57.510.16.1

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 40% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 10% of December, with mostly cloudy or overcast conditions the remaining 51%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15347
25347
35248
45149
55050
65149
75149
85050
95050
105050
115050
125050
135050
145050
155050
165149
175149
185149
195149
205050
215050
224951
234951
244852
254852
264753
274753
284753
294753
304753
314753

Chance of precipitation in December

Any precipitation

San Antonio gets around 2.5 in of rain over 7.5 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 24% and peaks near 26% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
123
224
324
424
525
625
725
826
926
1026
1126
1226
1326
1426
1525
1625
1725
1825
1924
2024
2124
2224
2323
2423
2523
2623
2723
2823
2923
3023
3123

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 81% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
1778114
2778114
3778114
4788104
5788104
679894
778994
878994
980983
1080983
1180983
1280983
13811072
14811072
15811072
16811072
17811072
18831061
19831061
20831061
21821062
2283962
2384952
2484952
2584952
2684952
2785852
2886842
2986842
3086842
3186842

Wind in December

Winds average 7 mph in December.

Across December, daily wind ranges from about 7 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 10 h 18 min at the start of December to 10 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 7:16 AM to 7:33 AM, and sunset from 5:31 PM to 5:41 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.37:165:31
210.27:175:31
310.27:185:31
410.27:185:31
510.27:195:31
610.27:205:32
710.27:215:32
810.27:215:32
910.27:225:32
1010.27:235:32
1110.27:235:32
1210.17:245:33
1310.17:255:33
1410.17:255:33
1510.17:265:34
1610.17:265:34
1710.17:275:34
1810.17:285:35
1910.17:285:35
2010.17:295:35
2110.17:295:36
2210.17:305:36
2310.17:305:37
2410.17:305:37
2510.17:315:38
2610.17:315:38
2710.17:325:39
2810.17:325:39
2910.17:325:40
3010.17:335:41
3110.17:335:41

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 2.72 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 2.72 kWh/m² to a high of 6.71 kWh/m² in July across the year — December's 2.72 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
12.8Moderate
22.8Moderate
32.8Moderate
42.8Moderate
52.8Moderate
62.8Moderate
72.7Moderate
82.7Moderate
92.7Moderate
102.7Moderate
112.7Moderate
122.7Moderate
132.7Moderate
142.7Moderate
152.7Moderate
162.7Moderate
172.7Moderate
182.7Moderate
192.7Moderate
202.7Moderate
212.7Moderate
222.7Moderate
232.7Moderate
242.8Moderate
252.8Moderate
262.8Moderate
272.8Moderate
282.8Moderate
292.8Moderate
302.8Moderate
312.8Moderate
Planning a trip in December

Is December a good time to visit San Antonio?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

6.1
Sightseeing
6th-best month of the year
1.9
Beach & pool
11th-best month of the year

December is a reasonable time to visit San Antonio for sightseeing.

What to pack for San Antonio in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, San Antonio sees daytime highs around 64°F and nights near 44°F. Worth packing: a warm layer. About 8 days see rain.

a warm layer

UV index in San Antonio in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 4 — 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 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateAug 11UV 11Dec 20UV 4
UV index (midday)Level
Jan4Moderate
Feb6High
Mar7Very high
Apr10Very high
May10Extreme
Jun11Extreme
Jul11Extreme
Aug11Extreme
Sep9Very high
Oct6High
Nov5High
Dec4Moderate

Air quality in San Antonio in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in San Antonio is worst in July — around 18 µg/m³ PM2.5 (moderate), about 2.8× the cleanest month (October, 6 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1317 µg/m³Oct 246 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb7Good
Mar9Good
Apr10Good
May15Moderate
Jun15Moderate
Jul18Moderate
Aug12Good
Sep10Good
Oct6Good
Nov6Good
Dec7Good
Location & terrain

Where is San Antonio?

San Antonio sits at 29.4°N, 98.5°W, 650 ft above sea level, in United States. The nearest listed city is Converse, 12 mi away.

Topography around San Antonio

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of San Antonio.

Within 2 miles, the terrain around San Antonio has only modest variations in elevation — a maximum elevation change of 174 ft around an average of 669 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 607 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 1,827 ft.

The land around San Antonio is covered by artificial surfaces (75%) within 2 miles, trees (38%), artificial surfaces (38%) and grassland (20%) within 10 miles, and trees (50%) and grassland (38%) within 50 miles.

2 miles
174 ft
10 miles
607 ft
50 miles
1,827 ft
treesshrubsgrasslandcroplandartificial surfacesbare terrain
December weather nearby: Converse 12 mi · Live Oak 14 mi · Universal City 15 mi · Schertz 16 mi · Cibolo 19 mi · New Braunfels 29 mi · Seguin 34 mi · Canyon Lake 34 mi

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
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

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 (29.4241°, -98.4936°, elevation 650 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).