Castaños weather in December

In December, Castaños sees average daytime highs of 19°C and overnight lows near 7°C, with 19 mm of precipitation across 3.4 wet days and about 10.3 hours of daylight. It is the 11th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 20°C in the first days to 18°C by the end. The sky is clear or mostly clear about 54% of the time in December, and the air most often feels dry.

Daylight stretches from about 10 h 24 min at the start of December to 10 h 18 min by month's end. Set against the rest of the year, December is Castaños's 8th-clearest and 12th-windiest month. For the whole year in context, see Castaños's year-round climate.

Daytime high
19°
11th warmest
Overnight low
2nd coldest
Precipitation
19 mm
3.4 wet days
Daylight
10 h 18 min
7:32 AM – 5:52 PM
Cloud cover
43%
8th clearest
Wind
6 km/h
12th windiest
Solar energy
3.69 kWh/m²
Travel score
7.4
out of 10

Castaños is municipal seat of Castaños, State of Coahuila, Mexico.

Founded
1674

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 20°C in the first days to 18°C by the end.

A typical December day in Castaños reaches about 19°C in the afternoon and slips back to 7°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 11°C and 27°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)
1219
2219
3209
4208
5208
6208
7208
8208
9208
10208
11208
12208
13207
14197
15197
16197
17197
18197
19197
20197
21197
22197
23197
24197
25187
26187
27186
28186
29186
30186
31186

How December really feels in Castaños

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.

Castaños weather by month

How December compares with the rest of the year at a glance. December is the 11th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan19° / 173.610.57.2
Feb22° / 123.111.18.0
Mar25° / 13°244.311.88.0
Apr29° / 16°275.812.66.2
May32° / 20°4911.613.34.3
Jun33° / 22°5610.213.73.8
Jul32° / 22°8110.213.54.0
Aug32° / 22°649.212.94.3
Sep28° / 19°1211312.25.6
Oct26° / 15°396.711.47.6
Nov22° / 11°213.910.78.0
Dec19° / 193.410.37.4

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 54% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 9% of December, with mostly cloudy or overcast conditions the remaining 37%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16634
26436
36337
46337
56139
66139
76139
86139
96139
106139
116139
126238
136238
146436
156436
166436
176436
186535
196535
206436
216436
226436
236436
246337
256238
266238
276139
286139
296139
306139
316139

Chance of precipitation in December

Any precipitation

Castaños gets around 19 mm of rain and snow over 3.4 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 11% and peaks near 12% on the wettest days, and about 0 day brings snow.

0%10%20%30%151015202531
Rain chance (%)
19
29
39
49
510
610
710
810
910
1010
1110
1211
1311
1411
1511
1611
1711
1811
1911
2011
2111
2211
2312
2412
2512
2612
2712
2812
2912
3012
3112

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 96% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19181
29181
39370
49370
59370
69460
79460
89550
99550
109550
119640
129640
139640
149640
159730
169730
179730
189730
199730
209730
219730
229730
239730
249730
259730
269730
279730
289730
299820
309820
319820

Wind in December

Winds average 6 km/h in December, the calmest month.

Across December, daily wind ranges from about 6 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
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 10 h 24 min at the start of December to 10 h 18 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 7:22 AM to 7:39 AM, and sunset from 5:49 PM to 5:59 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.47:225:49
210.47:235:49
310.47:245:49
410.47:255:49
510.47:255:49
610.47:265:49
710.47:275:49
810.47:275:49
910.47:285:50
1010.47:295:50
1110.37:295:50
1210.37:305:50
1310.37:305:51
1410.37:315:51
1510.37:325:51
1610.37:325:52
1710.37:335:52
1810.37:335:52
1910.37:345:53
2010.37:345:53
2110.37:355:54
2210.37:355:54
2310.37:365:55
2410.37:365:55
2510.37:375:56
2610.37:375:56
2710.37:375:57
2810.37:385:57
2910.37:385:58
3010.37:385:58
3110.37:395:59

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 3.69 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 3.69 kWh/m² to a high of 7.06 kWh/m² in June across the year — December's 3.69 kWh/m² sits near the bottom.

01234151015202531
Solar energy (kWh/m²)Level
13.8Moderate
23.8Moderate
33.8Moderate
43.7Moderate
53.7Moderate
63.7Moderate
73.7Moderate
83.7Moderate
93.7Moderate
103.7Moderate
113.7Moderate
123.7Moderate
133.6Moderate
143.6Moderate
153.6Moderate
163.6Moderate
173.6Moderate
183.7Moderate
193.7Moderate
203.7Moderate
213.7Moderate
223.7Moderate
233.7Moderate
243.7Moderate
253.7Moderate
263.7Moderate
273.7Moderate
283.7Moderate
293.7Moderate
303.7Moderate
313.7Moderate
Planning a trip in December

Hazard calendar for Castaños

In seasonPeak

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

Castaños's rainy season runs June–September, when most of the year's rain falls.

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

Is December a good time to visit Castaños?

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

7.4
Sightseeing
5th-best month of the year
3.4
Beach & pool
11th-best month of the year

December is one of the better times to visit Castaños for general sightseeing.

What to pack for Castaños in December

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

In December, Castaños sees daytime highs around 19°C and nights near 7°C. Worth packing: a warm layer. About 3 days see rain.

a warm layer

UV index in Castaños 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 Castaños peaks around July 15 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 5 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecHighVery highExtremeVery highHighJul 15UV 12Dec 17UV 5
UV index (midday)Level
Jan6High
Feb7Very high
Mar9Very high
Apr11Extreme
May12Extreme
Jun12Extreme
Jul12Extreme
Aug11Extreme
Sep11Extreme
Oct8Very high
Nov6High
Dec5Moderate

Air quality in Castaños 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 Castaños is worst in July — around 18 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (January, 9 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1617 µg/m³Jan 219 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb9Good
Mar9Good
Apr11Good
May15Moderate
Jun15Moderate
Jul18Moderate
Aug15Moderate
Sep14Moderate
Oct11Good
Nov10Good
Dec9Good
Location & terrain

Where is Castaños?

Castaños sits at 26.8°N, 101.4°W, 756 m above sea level, in Mexico. The nearest listed city is Monclova, 13 km away.

Topography around Castaños

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

Within 3 km, the terrain around Castaños has only modest variations in elevation — a maximum elevation change of 240 m around an average of 777 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,344 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,316 m.

The land around Castaños is covered by shrubs (58%) and artificial surfaces (26%) within 3 km, shrubs (81%) within 16 km, and shrubs (88%) within 80 km.

3 km
240 m
16 km
1,344 m
80 km
2,316 m
treesshrubsgrasslandcroplandartificial surfacesbare terrain
December weather nearby: Monclova 13 km · Frontera 16 km · San Buenaventura 32 km · Ciudad Melchor Múzquiz 121 km · Sabinas 123 km · Palaú 123 km · Ciudad Sabinas Hidalgo 128 km · Nueva Rosita 129 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 Castaños (26.7893°, -101.4321°, elevation 756 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).