Luján weather in December

In December, Luján sees average daytime highs of 28°C and overnight lows near 17°C, with 93 mm of rain across 8.8 wet days and about 14.3 hours of daylight. It is the 2nd-warmest and 5th-wettest month of the year here.

Highs climb over the month, from about 27°C in the first days to 29°C by the end. The sky is clear or mostly clear about 52% of the time in December, and the air most often feels humid.

Daylight stretches from about 14 h 06 min at the start of December to 14 h 18 min by month's end. Set against the rest of the year, December is Luján's 1st-clearest and 5th-windiest month. For the whole year in context, see Luján's year-round climate.

Daytime high
28°
2nd warmest
Overnight low
17°
10th coldest
Rainfall
93 mm
8.8 wet days
Daylight
14 h 18 min
5:44 AM – 8:02 PM
Cloud cover
43%
1st clearest
Wind
13 km/h
5th windiest
Solar energy
7.44 kWh/m²
Travel score
6.4
out of 10

Luján is city in Buenos Aires Province, Argentina.

Founded
1738

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 27°C in the first days to 29°C by the end.

A typical December day in Luján reaches about 28°C in the afternoon and slips back to 17°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 23°C and 33°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)
12715
22715
32715
42715
52715
62716
72716
82816
92816
102816
112816
122816
132816
142816
152816
162817
172817
182817
192917
202917
212917
222917
232917
242917
252918
262918
272918
282918
292918
302918
312918

Luján weather by month

How December compares with the rest of the year at a glance. December is the 2nd-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 18°917.814.15.8
Feb28° / 18°1018.313.36.3
Mar26° / 16°927.312.37.3
Apr23° / 12°968.311.27.2
May19° / 665.910.26.6
Jun16° / 545.89.75.3
Jul15° / 585.89.95.0
Aug17° / 615.510.76.2
Sep19° / 716.511.86.7
Oct22° / 12°1199.312.96.9
Nov25° / 14°948.213.87.2
Dec28° / 17°938.814.36.4

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 52% of the time in December, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 13% of December, with mostly cloudy or overcast conditions the remaining 35%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16337
26436
36535
46535
56634
66634
76634
86634
96535
106535
116535
126535
136535
146535
156535
166535
176535
186535
196535
206535
216535
226535
236535
246337
256337
266337
276337
286337
296337
306436
316436

Chance of precipitation in December

Any precipitation

Luján gets around 93 mm of rain over 8.8 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 28% and peaks near 30% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
126
226
326
427
527
627
727
827
927
1028
1128
1228
1329
1429
1529
1630
1730
1830
1930
2030
2129
2229
2329
2429
2529
2629
2728
2828
2928
3028
3128

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 29% of days. Sticky, muggy-or-worse air turns up on roughly 18% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
139272670
240262770
340262770
439252781
539252781
639252781
738252781
837262891
936262891
1035272891
11342728101
12332828101
13322828101
14302929112
15292929112
16282929122
17272830132
18252830142
19242730163
20232730173
21222630183
22212530204
23202430214
24192330234
25192230245
26182130255
27182130266
28172029276
29172029286
30161929297
31161929297

Wind in December

Winds average 13 km/h in December.

Across December, daily wind ranges from about 13 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2113light breeze
2213light breeze
2313light breeze
2413light breeze
2513light breeze
2613light breeze
2713light breeze
2813light breeze
2913light breeze
3013light breeze
3113light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 14 h 06 min at the start of December to 14 h 18 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 5:42 AM to 5:51 AM, and sunset from 7:51 PM to 8:08 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.15:427:51
214.25:427:51
314.25:427:52
414.25:427:53
514.25:427:54
614.25:427:55
714.25:427:55
814.25:427:56
914.35:427:57
1014.35:427:58
1114.35:427:58
1214.35:427:59
1314.35:438:00
1414.35:438:00
1514.35:438:01
1614.35:448:02
1714.35:448:02
1814.35:448:03
1914.35:458:03
2014.35:458:04
2114.35:458:04
2214.35:468:05
2314.35:468:05
2414.35:478:06
2514.35:478:06
2614.35:488:07
2714.35:498:07
2814.35:498:07
2914.35:508:08
3014.35:508:08
3114.35:518:08

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 7.44 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.26 kWh/m² to a high of 7.44 kWh/m² in December across the year — December's 7.44 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
17.3Intense
27.3Intense
37.4Intense
47.4Intense
57.4Intense
67.4Intense
77.4Intense
87.4Intense
97.5Intense
107.5Intense
117.5Intense
127.5Intense
137.4Intense
147.4Intense
157.4Intense
167.4Intense
177.4Intense
187.4Intense
197.4Intense
207.4Intense
217.4Intense
227.4Intense
237.4Intense
247.4Intense
257.4Intense
267.4Intense
277.4Intense
287.4Intense
297.4Intense
307.3Intense
317.3Intense
Planning a trip in December

Is December a good time to visit Luján?

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

6.4
Sightseeing
7th-best month of the year
7.3
Beach & pool
2nd-best month of the year

December is a reasonable time to visit Luján for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Luján in December

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

In December, Luján sees daytime highs around 28°C and nights near 17°C. Pack light clothes and sun protection. Worth having: rain gear. About 9 days see rain.

light clothessun protectionrain gear

Sea temperature near Luján in December

The nearest coast averages about 23°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 68 km away) is warmest in January at about 25°C and coldest in July near 13°C.

It's comfortable for a long swim from Nov 9 to Apr 20 — about 5.4 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swimcomfortable to swim
Sea temperature (°C)Comfort
Jan25Warm
Feb25Warm
Mar23Refreshing
Apr21Refreshing
May17Cool
Jun14Bracing
Jul13Bracing
Aug13Bracing
Sep15Cool
Oct18Cool
Nov21Refreshing
Dec23Refreshing

UV index in Luján 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 Luján peaks around January 14 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 14UV 13Jun 19UV 3
UV index (midday)Level
Jan13Extreme
Feb11Extreme
Mar9Very high
Apr6High
May4Moderate
Jun3Moderate
Jul3Moderate
Aug4Moderate
Sep6High
Oct8Very high
Nov11Extreme
Dec12Extreme

Air quality in Luján 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 Luján is worst in August — around 20 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (November, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodGoodModerateGoodAug 1619 µg/m³Nov 2310 µg/m³
PM2.5 (µg/m³)Level
Jan12Moderate
Feb11Good
Mar12Moderate
Apr11Good
May14Moderate
Jun16Moderate
Jul16Moderate
Aug20Moderate
Sep15Moderate
Oct13Moderate
Nov10Good
Dec11Good
Location & terrain

Where is Luján?

Luján sits at 34.6°S, 59.1°W, 17 m above sea level, in Argentina. The nearest listed city is Pilar, 22 km away.

Topography around Luján

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

Within 3 km, the terrain around Luján has only modest variations in elevation — a maximum elevation change of 25 m around an average of 24 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 62 m; within 80 km, only modest variations in elevation — a maximum elevation change of 83 m.

The land around Luján is covered by artificial surfaces (49%), trees (26%) and grassland (20%) within 3 km, cropland (52%) and grassland (28%) within 16 km, and cropland (42%) and grassland (27%) within 80 km.

3 km
25 m
16 km
62 m
80 km
83 m
treesgrasslandcroplandartificial surfaceswaterwetland
December weather nearby: Pilar 22 km · Mercedes 30 km · Moreno 31 km · José C. Paz 32 km · Tortuguitas 35 km · San Miguel 37 km · Merlo 37 km · Muñiz 37 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 Luján (-34.5664°, -59.1148°, elevation 17 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. 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).