San Luis Río Colorado weather in December

In December, San Luis Río Colorado sees average daytime highs of 21°C and overnight lows near 9°C, with 9 mm of rain across 1.7 wet days and about 9.9 hours of daylight. It is the 12th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 22°C in the first days to 20°C by the end. The sky is clear or mostly clear about 64% of the time in December, and the air most often feels dry.

Daylight stretches from about 10 hours at the start of December to 9 h 54 min by month's end. Set against the rest of the year, December is San Luis Río Colorado's 10th-clearest and 7th-windiest month. For the whole year in context, see San Luis Río Colorado's year-round climate.

Daytime high
21°
12th warmest
Overnight low
1st coldest
Rainfall
9 mm
1.7 wet days
Daylight
9 h 54 min
7:39 AM – 5:32 PM
Cloud cover
32%
10th clearest
Wind
10 km/h
7th windiest
Solar energy
3.4 kWh/m²
Travel score
8.2
out of 10

San Luis Río Colorado is municipal seat of San Luis, State of Sonora, Mexico.

Founded
1918

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 22°C in the first days to 20°C by the end.

A typical December day in San Luis Río Colorado reaches about 21°C in the afternoon and slips back to 9°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 16°C and 25°C. Set against its neighbours, December runs about 5°C cooler than November and about 1°C cooler than January.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
12210
22210
32210
42210
52210
62210
72110
82110
9219
10219
11219
12219
13219
14219
15219
16209
17209
18209
19209
20209
21209
22209
23208
24208
25208
26208
27208
28208
29209
30209
31209

How December really feels in San Luis Río Colorado

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 Luis Río Colorado weather by month

How December compares with the rest of the year at a glance. December is the 12th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan22° / 10°91.510.18.4
Feb24° / 11°132.310.88.6
Mar27° / 13°101.511.88.1
Apr31° / 16°30.612.86.1
May35° / 20°10.213.63.5
Jun39° / 24°10.214.10.7
Jul41° / 28°51.513.90.0
Aug41° / 29°112.913.20.0
Sep38° / 25°132.212.21.2
Oct33° / 19°50.911.24.9
Nov26° / 13°60.810.38.6
Dec21° / 91.79.98.2

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 64% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 11% of December, with mostly cloudy or overcast conditions the remaining 25%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17624
27624
37624
47624
57525
67525
77525
87525
97525
107525
117525
127624
137624
147624
157525
167525
177525
187525
197525
207426
217426
227426
237426
247426
257327
267327
277327
287327
297327
307327
317327

Chance of precipitation in December

Any precipitation

San Luis Río Colorado gets around 9 mm of rain over 1.7 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 5% and peaks near 6% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
15
25
35
45
55
65
75
85
95
105
115
125
135
145
155
165
175
186
196
206
216
226
236
246
256
266
276
286
296
306
316

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 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1991
2991
3991
4991
5991
6991
7991
8991
9991
10991
111000
121000
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000
311000

Wind in December

Winds average 10 km/h in December.

Across December, daily wind ranges from about 10 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm
3110calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 10 hours at the start of December to 9 h 54 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 7:28 AM to 7:45 AM, and sunset from 5:30 PM to 5:39 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.07:285:30
210.07:295:29
310.07:305:29
410.07:315:29
510.07:315:29
610.07:325:30
79.97:335:30
89.97:345:30
99.97:345:30
109.97:355:30
119.97:365:30
129.97:365:30
139.97:375:31
149.97:385:31
159.97:385:31
169.97:395:32
179.97:395:32
189.97:405:32
199.97:415:33
209.97:415:33
219.97:425:34
229.97:425:34
239.97:435:35
249.97:435:35
259.97:435:36
269.97:445:36
279.97:445:37
289.97:445:37
299.97:455:38
309.97:455:38
319.97:455:39

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 3.4 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 3.4 kWh/m² to a high of 8.49 kWh/m² in June across the year — December's 3.4 kWh/m² sits near the bottom.

01234151015202531
Solar energy (kWh/m²)Level
13.5Moderate
23.5Moderate
33.5Moderate
43.5Moderate
53.5Moderate
63.4Moderate
73.4Moderate
83.4Moderate
93.4Moderate
103.4Moderate
113.4Moderate
123.4Moderate
133.4Moderate
143.3Moderate
153.3Moderate
163.3Moderate
173.3Moderate
183.3Moderate
193.3Moderate
203.3Moderate
213.3Moderate
223.4Moderate
233.4Moderate
243.4Moderate
253.4Moderate
263.4Moderate
273.4Moderate
283.4Moderate
293.4Moderate
303.5Moderate
313.5Moderate
Planning a trip in December

Is December a good time to visit San Luis Río Colorado?

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

8.2
Sightseeing
4th-best month of the year
4.8
Beach & pool
8th-best month of the year

December is one of the better times to visit San Luis Río Colorado for general sightseeing.

What to pack for San Luis Río Colorado in December

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

In December, San Luis Río Colorado sees daytime highs around 21°C and nights near 9°C. Little to plan around — just the basics.

UV index in San Luis Río Colorado in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 3 — 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 Luis Río Colorado peaks around June 23 at about 11 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 18 at about 3 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateVery highExtremeVery highHighModerateJun 23UV 11Dec 18UV 3
UV index (midday)Level
Jan4Moderate
Feb5Moderate
Mar5Moderate
Apr8Very high
May8Very high
Jun11Extreme
Jul11Extreme
Aug10Very high
Sep9Very high
Oct6High
Nov4Moderate
Dec3Moderate
Location & terrain

Where is San Luis Río Colorado?

San Luis Río Colorado sits at 32.5°N, 114.8°W, 36 m above sea level, in Mexico. The nearest listed city is San Luis, 4.0 km away.

Topography around San Luis Río Colorado

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

Within 3 km, the terrain around San Luis Río Colorado has only modest variations in elevation — a maximum elevation change of 24 m around an average of 44 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 53 m; within 80 km, large variations in elevation — a maximum elevation change of 1,108 m.

The land around San Luis Río Colorado is covered by artificial surfaces (83%) within 3 km, bare terrain (56%) and cropland (32%) within 16 km, and bare terrain (73%) within 80 km.

3 km
24 m
16 km
53 m
80 km
1,108 m
treesshrubscroplandartificial surfacesbare terrainwaterwetland
December weather nearby: San Luis 4.0 km · Somerton 17 km · Yuma 33 km · Ciudad Guadalupe Victoria 36 km · Fortuna Foothills 40 km · Puebla 56 km · Mexicali 67 km · Calexico 73 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 Luis Río Colorado (32.4555°, -114.7704°, elevation 36 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).