San Nicolás de los Arroyos weather in December

In December, San Nicolás de los Arroyos sees average daytime highs of 29°C and overnight lows near 18°C, with 107 mm of rain across 8.6 wet days and about 14.2 hours of daylight. It is the 2nd-warmest and 4th-wettest month of the year here.

Highs climb over the month, from about 28°C in the first days to 30°C by the end. The sky is clear or mostly clear about 50% of the time in December, and the air most often feels humid.

Daylight stretches from about 14 hours at the start of December to 14 h 12 min by month's end. Set against the rest of the year, December is San Nicolás de los Arroyos's 3rd-clearest and 6th-windiest month. For the whole year in context, see San Nicolás de los Arroyos's year-round climate.

Daytime high
29°
2nd warmest
Overnight low
18°
10th coldest
Rainfall
107 mm
8.6 wet days
Daylight
14 h 12 min
5:51 AM – 8:03 PM
Cloud cover
43%
3rd clearest
Wind
11 km/h
6th windiest
Solar energy
7.31 kWh/m²
Travel score
6.0
out of 10

San Nicolás de los Arroyos is city in Argentina.

Founded
1748

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

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 28°C in the first days to 30°C by the end.

A typical December day in San Nicolás de los Arroyos reaches about 29°C in the afternoon and slips back to 18°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 24°C and 34°C. Set against its neighbours, December runs about 3°C warmer than November and about 1°C cooler than January.

10°15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12817
22817
32817
42817
52817
62817
72817
82817
92817
102917
112917
122917
132918
142918
152918
162918
172918
182918
192918
202918
212918
222919
233019
243019
253019
263019
273019
283019
293019
303019
313019

San Nicolás de los Arroyos weather by month

How December compares with the rest of the year at a glance. December is the 2nd-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 19°1038.2145.4
Feb29° / 19°1078.113.25.9
Mar27° / 17°1177.512.37.0
Apr23° / 14°1068.111.27.4
May19° / 11°66610.36.8
Jun16° / 445.29.85.8
Jul16° / 425.1105.6
Aug18° / 56510.86.8
Sep21° / 10°676.311.87.1
Oct23° / 13°1129.712.87.1
Nov26° / 15°1157.613.77.2
Dec29° / 18°1078.614.26.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 50% 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 36%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16238
26337
36337
46436
56436
66535
76535
86535
96634
106634
116634
126634
136634
146634
156535
166535
176535
186436
196436
206436
216337
226337
236238
246238
256238
266139
276139
286139
296139
306139
316139

Chance of precipitation in December

Any precipitation

San Nicolás de los Arroyos gets around 107 mm of rain over 8.6 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 28% and peaks near 30% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
126
226
326
426
526
626
727
827
927
1028
1128
1229
1329
1430
1530
1630
1730
1830
1930
2030
2130
2229
2329
2428
2528
2628
2727
2827
2926
3026
3126

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the humid band about 31% of days. Sticky, muggy-or-worse air turns up on roughly 26% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
12930281110
22929291210
32929291210
42828301320
52827301320
62727311320
72726311420
82626321420
92525321520
102425331520
112425331620
122324341630
132224341730
142124351830
152023351930
161923352030
171822342140
181722342240
191722342350
201621332450
211521322560
221421322670
231420312780
241320302890
2512202929100
2612202829110
2711202830120
2811202730120
2910192731130
309192631141
319192631151

Wind in December

Winds average 11 km/h in December.

Across December, daily wind ranges from about 11 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm
3111calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 14 hours at the start of December to 14 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 12 minutes over December. Sunrise moves from 5:49 AM to 5:59 AM, and sunset from 7:52 PM to 8:09 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.05:497:52
214.15:497:53
314.15:497:54
414.15:497:54
514.15:497:55
614.15:497:56
714.15:497:57
814.15:497:58
914.15:497:58
1014.25:507:59
1114.25:508:00
1214.25:508:00
1314.25:508:01
1414.25:518:02
1514.25:518:02
1614.25:518:03
1714.25:518:03
1814.25:528:04
1914.25:528:05
2014.25:538:05
2114.25:538:06
2214.25:548:06
2314.25:548:07
2414.25:558:07
2514.25:558:07
2614.25:568:08
2714.25:568:08
2814.25:578:08
2914.25:578:09
3014.25:588:09
3114.25:598:09

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 7.31 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.34 kWh/m² to a high of 7.31 kWh/m² in December across the year — December's 7.31 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
17.2Intense
27.3Intense
37.3Intense
47.3Intense
57.3Intense
67.3Intense
77.3Intense
87.3Intense
97.3Intense
107.3Intense
117.3Intense
127.3Intense
137.3Intense
147.3Intense
157.3Intense
167.3Intense
177.3Intense
187.3Intense
197.3Intense
207.3Intense
217.3Intense
227.3Intense
237.2Intense
247.2Intense
257.2Intense
267.2Intense
277.2Intense
287.2Intense
297.2Intense
307.2Intense
317.2Intense
Planning a trip in December

Is December a good time to visit San Nicolás de los Arroyos?

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

6.0
Sightseeing
8th-best month of the year
7.4
Beach & pool
2nd-best month of the year

December is a reasonable time to visit San Nicolás de los Arroyos for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for San Nicolás de los Arroyos in December

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

In December, San Nicolás de los Arroyos sees daytime highs around 29°C and nights near 18°C. Pack light clothes and sun protection. Worth having: rain gear. About 9 days see rain.

light clothessun protectionrain gear

UV index in San Nicolás de los Arroyos in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 12 (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 Nicolás de los Arroyos peaks around January 15 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 19 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateHighVery highExtremeJan 15UV 13Jun 19UV 3
UV index (midday)Level
Jan14Extreme
Feb12Extreme
Mar10Very high
Apr6High
May4Moderate
Jun3Moderate
Jul3Moderate
Aug4Moderate
Sep6High
Oct9Very high
Nov11Extreme
Dec12Extreme

Air quality in San Nicolás de los Arroyos 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 Nicolás de los Arroyos is worst in August — around 46 µg/m³ PM2.5 (poor), about 8.0× the cleanest month (April, 6 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecGoodModeratePoorModerateGoodAug 1544 µg/m³Apr 146 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb7Good
Mar7Good
Apr6Good
May7Good
Jun10Good
Jul28Moderate
Aug46Poor
Sep20Moderate
Oct14Moderate
Nov8Good
Dec7Good
Location & terrain

Where is San Nicolás de los Arroyos?

San Nicolás de los Arroyos sits at 33.3°S, 60.2°W, 28 m above sea level, in Argentina. The nearest listed city is Villa Constitución, 16 km away.

Topography around San Nicolás de los Arroyos

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Nicolás de los Arroyos.

Within 3 km, the terrain around San Nicolás de los Arroyos has only modest variations in elevation — a maximum elevation change of 38 m around an average of 16 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 53 m; within 80 km, only modest variations in elevation — a maximum elevation change of 98 m.

The land around San Nicolás de los Arroyos is covered by artificial surfaces (42%) within 3 km, cropland (39%) and wetland (32%) within 16 km, and cropland (50%) and wetland (31%) within 80 km.

3 km
38 m
16 km
53 m
80 km
98 m
treesgrasslandcroplandartificial surfaceswaterwetland
December weather nearby: Villa Constitución 16 km · Ramallo 25 km · Arroyo Seco 34 km · Gobernador Gálvez 52 km · Rosario 59 km · San Pedro 63 km · Pérez 64 km · Pergamino 70 km

Argentina travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / I
220 V · 50 Hz
Prices
≈ 46% of US
price level, 2025
GDP per capita
$14,898
2025
Happiness
6.4 / 10
World Happiness, 2025
Homicide rate
4.5
per 100k, 2023
Road deaths
14.1
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
High
EF EPI 575
Religion
Roman Catholic 63%none 19%Evangelical 15%Jehovah's Witness and Church of Jesus Christ 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 Nicolás de los Arroyos (-33.3342°, -60.2108°, elevation 28 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).