San Fernando weather in December

In December, San Fernando sees average daytime highs of 23°C and overnight lows near 13°C, with 24 mm of rain across 4.1 wet days and about 10.5 hours of daylight. It is the 11th-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 25°C in the first days to 22°C 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 36 min at the start of December to 10 h 30 min by month's end. Set against the rest of the year, December is San Fernando's 10th-clearest and 7th-windiest month. For the whole year in context, see San Fernando's year-round climate.

Daytime high
23°
11th warmest
Overnight low
13°
2nd coldest
Rainfall
24 mm
4.1 wet days
Daylight
10 h 30 min
7:15 AM – 5:43 PM
Cloud cover
52%
10th clearest
Wind
14 km/h
7th windiest
Solar energy
3.35 kWh/m²
Travel score
7.9
out of 10

San Fernando is municipal seat of San Fernando, State of Tamaulipas, Mexico.

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 25°C in the first days to 22°C by the end.

A typical December day in San Fernando reaches about 23°C in the afternoon and slips back to 13°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 16°C and 29°C. Set against its neighbours, December runs about 3°C cooler than November and on par with January.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
12514
22514
32514
42514
52414
62414
72414
82414
92414
102414
112413
122413
132413
142413
152413
162313
172313
182313
192313
202313
212313
222313
232312
242312
252312
262312
272212
282212
292212
302212
312212

How December really feels in San Fernando

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

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
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 Fernando weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan23° / 12°254.410.67.7
Feb25° / 14°203.911.17.8
Mar28° / 17°324.911.86.8
Apr31° / 20°455.212.65.1
May33° / 23°496.513.23.8
Jun35° / 25°639.913.52.8
Jul35° / 25°698.813.42.6
Aug35° / 25°579.512.92.4
Sep33° / 23°11914.512.23.3
Oct30° / 20°678.211.45.4
Nov26° / 16°355.310.87.5
Dec23° / 13°244.110.57.9

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 14% of December, with mostly cloudy or overcast conditions the remaining 45%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16040
26040
35941
45842
55842
65644
75644
85545
95545
105446
115446
125446
135446
145446
155446
165446
175545
185545
195545
205545
215545
225446
235446
245347
255347
265248
275248
285248
295149
305149
315149

Chance of precipitation in December

Any precipitation

San Fernando gets around 24 mm of rain over 4.1 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 13% and peaks near 14% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
113
213
313
413
513
613
713
813
913
1013
1113
1213
1313
1413
1513
1613
1713
1813
1913
2013
2113
2213
2313
2414
2514
2614
2714
2814
2914
3014
3114

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 49% of days. Sticky, muggy-or-worse air turns up on roughly 17% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1381721232
2381720222
3391720223
4401720213
5401720203
6411720203
7421719193
8431619193
9441619192
10451618182
11461618182
12471617172
13491617172
14501617162
15511517161
16521517151
17521517151
18531517141
19531517141
20541517131
21541517131
22551517121
23561517120
24561518110
25561518110
26571518100
27561519100
2857151990
2956161990
3056161990
3156161990

Wind in December

Winds average 14 km/h in December.

Across December, daily wind ranges from about 14 km/h on the calmest days to 14 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light breeze
3114light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 10 h 36 min at the start of December to 10 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 7:05 AM to 7:21 AM, and sunset from 5:39 PM to 5:50 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.67:055:39
210.67:065:39
310.57:075:40
410.57:075:40
510.57:085:40
610.57:095:40
710.57:095:40
810.57:105:40
910.57:115:41
1010.57:115:41
1110.57:125:41
1210.57:125:41
1310.57:135:42
1410.57:145:42
1510.57:145:42
1610.57:155:43
1710.57:155:43
1810.57:165:43
1910.57:165:44
2010.57:175:44
2110.57:175:45
2210.57:185:45
2310.57:185:46
2410.57:195:46
2510.57:195:47
2610.57:205:47
2710.57:205:48
2810.57:205:48
2910.57:215:49
3010.57:215:49
3110.57:215:50

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 3.35 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 3.35 kWh/m² to a high of 6.8 kWh/m² in July across the year — December's 3.35 kWh/m² sits near the bottom.

01234151015202531
Solar energy (kWh/m²)Level
13.5Moderate
23.5Moderate
33.4Moderate
43.4Moderate
53.4Moderate
63.4Moderate
73.4Moderate
83.4Moderate
93.4Moderate
103.4Moderate
113.3Moderate
123.3Moderate
133.3Moderate
143.3Moderate
153.3Moderate
163.3Moderate
173.3Moderate
183.3Moderate
193.3Moderate
203.3Moderate
213.3Moderate
223.3Moderate
233.3Moderate
243.3Moderate
253.3Moderate
263.3Moderate
273.3Moderate
283.3Moderate
293.3Moderate
303.4Moderate
313.4Moderate
Planning a trip in December

Hazard calendar for San Fernando

In seasonPeak

None of San Fernando's seasonal hazards are active in December. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

San Fernando sits in the Atlantic hurricane belt; the season peaks August–October.

San Fernando's rainy season runs June–October, when most of the year's rain falls.

Atlantic hurricane
Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit San Fernando?

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

7.9
Sightseeing
1st-best month of the year
6.4
Beach & pool
7th-best month of the year

December is one of the better times to visit San Fernando for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for San Fernando in December

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

In December, San Fernando sees daytime highs around 23°C and nights near 13°C. Worth packing: light clothes. About 4 days see rain.

light clothes

Sea temperature near San Fernando in December

The nearest coast averages about 22°C in December — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 58 km away) is warmest in September at about 29°C and coldest in February near 20°C.

The water stays above 20°C all year — warm enough for a swim any month.

20°25°30°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan21Refreshing
Feb20Refreshing
Mar21Refreshing
Apr23Refreshing
May26Warm
Jun28Warm
Jul28Tropical
Aug29Tropical
Sep29Tropical
Oct28Warm
Nov25Warm
Dec22Refreshing

UV index in San Fernando in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 5 — 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 Fernando peaks around April 17 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near January 10 at about 5 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highExtremeVery highExtremeVery highHighApr 17UV 11Jan 10UV 5
UV index (midday)Level
Jan5High
Feb7High
Mar8Very high
Apr12Extreme
May9Very high
Jun11Extreme
Jul11Extreme
Aug11Extreme
Sep9Very high
Oct9Very high
Nov6High
Dec5High

Air quality in San Fernando 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 Fernando is worst in August — around 34 µg/m³ PM2.5 (moderate), about 5.6× the cleanest month (January, 6 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodAug 934 µg/m³Nov 186 µg/m³
PM2.5 (µg/m³)Level
Jan6Good
Feb8Good
Mar11Good
Apr14Moderate
May23Moderate
Jun28Moderate
Jul34Moderate
Aug34Moderate
Sep17Moderate
Oct7Good
Nov6Good
Dec6Good
Location & terrain

Where is San Fernando?

San Fernando sits at 24.8°N, 98.1°W, 44 m above sea level, in Mexico. The nearest listed city is Valle Hermoso, 98 km away.

Topography around San Fernando

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Fernando.

Within 3 km, the terrain around San Fernando has only modest variations in elevation — a maximum elevation change of 64 m around an average of 45 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 135 m; within 80 km, large variations in elevation — a maximum elevation change of 1,049 m.

The land around San Fernando is covered by trees (37%), artificial surfaces (29%) and shrubs (21%) within 3 km, cropland (35%), trees (30%) and shrubs (22%) within 16 km, and shrubs (30%) and cropland (21%) within 80 km.

3 km
64 m
16 km
135 m
80 km
1,049 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetland
December weather nearby: Valle Hermoso 98 km · Ciudad Río Bravo 127 km · Heroica Matamoros 132 km · Brownsville 134 km · Reynosa 138 km · Linares 143 km · Mercedes 147 km · Weslaco 147 km

Mexico travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / B
120 / 127 V · 60 Hz
Prices
≈ 54% of US
price level, 2025
GDP per capita
$13,889
2025
Happiness
7.0 / 10
World Happiness, 2025
Safe drinking water
43%
of population, 2024
Homicide rate
24.9
per 100k, 2023
Road deaths
12.8
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Very low
EF EPI 440
Religion
Catholic 78%no religion 11%other Evangelical Churches 8%Jehovah Witness 1%

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 Fernando (24.8471°, -98.1488°, elevation 44 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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. 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).