San Marcos weather in December

In December, San Marcos sees average daytime highs of 32°C and overnight lows near 24°C, with 96 mm of rain across 18.8 wet days and about 11.5 hours of daylight. It is the 9th-warmest and 9th-wettest month of the year here.

Day-to-day highs hold fairly steady near 32°C through the month. The sky is clear or mostly clear about 23% of the time in December, and the air most often feels miserable.

Daylight stretches from about 11 h 30 min at the start of December to 11 h 30 min by month's end. Set against the rest of the year, December is San Marcos's 4th-clearest and 7th-windiest month. For the whole year in context, see San Marcos's year-round climate.

Daytime high
32°
9th warmest
Overnight low
24°
2nd coldest
Rainfall
96 mm
18.8 wet days
Daylight
11 h 30 min
6:12 AM – 5:42 PM
Cloud cover
65%
4th clearest
Wind
5 km/h
7th windiest
Solar energy
4.67 kWh/m²
Travel score
3.3
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 32°C through the month.

A typical December day in San Marcos reaches about 32°C in the afternoon and slips back to 24°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 30°C and 33°C. Set against its neighbours, December runs on par with November and about 1°C cooler than January.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13124
23224
33224
43224
53224
63224
73224
83224
93224
103224
113224
123224
133224
143224
153224
163224
173224
183224
193224
203224
213224
223224
233224
243224
253224
263224
273224
283224
293224
303224
313224

How December really feels in San Marcos

Once humidity and wind are folded in, December averages 31 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
31
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in December is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

San Marcos weather by month

How December compares with the rest of the year at a glance. December is the 9th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan33° / 24°317.811.63.8
Feb35° / 25°316.911.72.9
Mar35° / 26°8015.211.92.3
Apr33° / 25°19825.712.22.1
May32° / 25°31029.312.42.1
Jun32° / 25°26027.112.52.2
Jul32° / 25°24427.312.52.3
Aug32° / 24°25828.312.32.2
Sep32° / 24°26528.912.12.2
Oct31° / 24°27329.811.82.3
Nov31° / 24°19627.211.62.5
Dec32° / 24°9618.811.53.3

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 23% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 17% of December, with mostly cloudy or overcast conditions the remaining 60%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12674
22773
32773
42872
52872
62872
72872
83070
93169
103169
113268
123466
133565
143763
153862
163961
174060
184258
194456
204555
214753
224852
234951
245050
255248
265248
275347
285446
295545
305644
315842

Chance of precipitation in December

Any precipitation

San Marcos gets around 96 mm of rain over 18.8 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 61% and peaks near 80% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
180
280
379
479
578
677
776
875
974
1073
1171
1269
1367
1466
1564
1662
1760
1858
1956
2054
2152
2250
2348
2446
2544
2643
2742
2840
2939
3039
3138

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the miserable band about 72% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Oppressive (%)Miserable (%)
12278
22278
32179
42179
52179
62179
72179
82278
92278
102278
112377
122377
132476
142575
152575
162674
172773
182872
192971
203070
213169
223268
233367
243466
253565
263565
273664
283763
293862
303961
314060

Wind in December

Winds average 5 km/h in December.

Across December, daily wind ranges from about 5 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 11 h 30 min at the start of December to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 0 minutes over December. Sunrise moves from 6:04 AM to 6:19 AM, and sunset from 5:36 PM to 5:49 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.56:045:36
211.56:055:36
311.56:055:37
411.56:065:37
511.56:065:37
611.56:075:38
711.56:075:38
811.56:085:38
911.56:085:39
1011.56:095:39
1111.56:095:40
1211.56:105:40
1311.56:105:40
1411.56:115:41
1511.56:115:41
1611.56:125:42
1711.56:125:42
1811.56:135:42
1911.56:135:43
2011.56:145:43
2111.56:145:44
2211.56:155:44
2311.56:155:45
2411.56:165:45
2511.56:165:46
2611.56:165:46
2711.56:175:47
2811.56:175:47
2911.56:185:48
3011.56:185:48
3111.56:195:49

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 4.67 kWh/m².

For context, solar energy here swings from a low near 4.41 kWh/m² to a high of 5.7 kWh/m² in March across the year — December's 4.67 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.5Bright
24.5Bright
34.5Bright
44.5Bright
54.5Bright
64.5Bright
74.5Bright
84.5Bright
94.5Bright
104.5Bright
114.6Bright
124.6Bright
134.6Bright
144.6Bright
154.6Bright
164.7Bright
174.7Bright
184.7Bright
194.7Bright
204.7Bright
214.8Bright
224.8Bright
234.8Bright
244.8Bright
254.8Bright
264.9Bright
274.9Bright
284.9Bright
294.9Bright
304.9Bright
315.0Bright
Planning a trip in December

Is December a good time to visit San Marcos?

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

3.3
Sightseeing
2nd-best month of the year
5.2
Beach & pool
3rd-best month of the year

December is a weaker month for outdoor sightseeing in San Marcos.

What to pack for San Marcos in December

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

In December, San Marcos sees daytime highs around 32°C and nights near 24°C. Pack light clothes and rain gear. Worth having: sun protection. About 19 days see rain.

light clothesrain gearsun protection

UV index in San Marcos in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in San Marcos peaks around June 15 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 at about 10 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highJun 15UV 13Dec 13UV 10
UV index (midday)Level
Jan11Extreme
Feb12Extreme
Mar12Extreme
Apr12Extreme
May12Extreme
Jun13Extreme
Jul12Extreme
Aug12Extreme
Sep12Extreme
Oct12Extreme
Nov10Very high
Dec10Very high

Air quality in San Marcos 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 Marcos is worst in March — around 34 µg/m³ PM2.5 (moderate), about 2.7× the cleanest month (November, 12 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 1933 µg/m³Nov 1812 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb21Moderate
Mar34Moderate
Apr27Moderate
May22Moderate
Jun20Moderate
Jul20Moderate
Aug17Moderate
Sep14Moderate
Oct13Moderate
Nov12Moderate
Dec13Moderate
Location & terrain

Where is San Marcos?

San Marcos sits at 8.7°N, 75.1°W, 25 m above sea level, in Colombia. The nearest listed city is San Benito Abad, 32 km away.

Topography around San Marcos

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

Within 3 km, the terrain around San Marcos has only modest variations in elevation — a maximum elevation change of 18 m around an average of 22 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 73 m; within 80 km, large variations in elevation — a maximum elevation change of 1,004 m.

The land around San Marcos is covered by grassland (57%) within 3 km, grassland (69%) within 16 km, and grassland (68%) within 80 km.

3 km
18 m
16 km
73 m
80 km
1,004 m
treesgrasslandcroplandartificial surfaceswaterwetland
December weather nearby: San Benito Abad 32 km · Ayapel 38 km · Sahagún 47 km · Sucre 48 km · Galeras 56 km · Planeta Rica 57 km · Chinú 58 km · Ciénaga de Oro 59 km

Colombia travel facts

Travel advisory
Level 3
Reconsider Travel
Power plugs
Type A / B
120 / 240 V · 60 Hz
Prices
≈ 38% of US
price level, 2025
GDP per capita
$8,562
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
74%
of population, 2024
Homicide rate
24.9
per 100k, 2023
Road deaths
15.4
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 480
Religion
Roman Catholic 64%Protestant 17%none 14%atheist 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 Marcos (8.6597°, -75.1281°, elevation 25 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. 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).