San Javier weather in December

In December, San Javier sees average daytime highs of 30°C and overnight lows near 19°C, with 137 mm of rain across 8.7 wet days and about 13.9 hours of daylight. It is the 2nd-warmest and 2nd-wettest month of the year here.

Highs climb over the month, from about 29°C in the first days to 31°C by the end. The sky is clear or mostly clear about 48% of the time in December, and the air most often feels muggy.

Daylight stretches from about 13 h 48 min at the start of December to 14 hours by month's end. Set against the rest of the year, December is San Javier's 6th-clearest and 6th-windiest month. For the whole year in context, see San Javier's year-round climate.

Daytime high
30°
2nd warmest
Overnight low
19°
10th coldest
Rainfall
137 mm
8.7 wet days
Daylight
14 hours
5:57 AM – 7:55 PM
Cloud cover
46%
6th clearest
Wind
11 km/h
6th windiest
Solar energy
7.1 kWh/m²
Travel score
5.3
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 29°C in the first days to 31°C by the end.

A typical December day in San Javier reaches about 30°C in the afternoon and slips back to 19°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 25°C and 35°C. Set against its neighbours, December runs about 2°C warmer than November and about 1°C cooler than January.

10°20°30°40°151015202531
Avg high (°C)Avg low (°C)
12918
22918
32918
42918
52918
62918
73019
83019
93019
103019
113019
123019
133019
143019
153019
163019
173019
183019
193020
203020
213020
223120
233120
243120
253120
263120
273120
283120
293120
303121
313121

How December really feels in San Javier

Once humidity and wind are folded in, December averages 6 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
6
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 Javier weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 21°1279.413.84.6
Feb30° / 20°1188.813.15.1
Mar28° / 18°1179.112.26.2
Apr25° / 15°1388.911.37.2
May21° / 12°83610.57.1
Jun18° / 10°615.610.16.6
Jul18° / 435.210.26.8
Aug21° / 10°635.310.97.4
Sep23° / 12°766.711.87.6
Oct25° / 15°1379.512.87.1
Nov28° / 17°1197.613.56.6
Dec30° / 19°1378.713.95.3

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 48% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 15% of December, with mostly cloudy or overcast conditions the remaining 37%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16238
26238
36337
46436
56436
66535
76535
86535
96634
106634
116634
126634
136634
146634
156535
166535
176337
186337
196238
206238
216238
226139
236139
246040
256040
266040
276040
286040
296040
306040
316139

Chance of precipitation in December

Any precipitation

San Javier gets around 137 mm of rain over 8.7 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 28% and peaks near 30% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
126
226
326
426
526
627
727
827
927
1027
1127
1227
1327
1428
1528
1628
1729
1829
1929
2029
2129
2229
2329
2430
2530
2629
2729
2829
2929
3029
3129

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the muggy band about 29% of days. Sticky, muggy-or-worse air turns up on roughly 46% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
11524312460
21424312470
31424312470
41423312470
51423302580
61422302580
71421302590
81421302690
913203026100
1013203027101
1112193028111
1212193028111
1311182929121
1411182929121
1510172930131
169162931141
179152931151
188152831162
198142832172
207142732182
217132732193
226132632203
236122631213
246122531224
256122531234
265112431244
275112430254
285122430255
294122330265
304122330275
314122329275

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 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
112calm
212calm
312calm
412calm
512calm
612calm
712calm
812calm
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 13 h 48 min at the start of December to 14 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 12 minutes over December. Sunrise moves from 5:54 AM to 6:04 AM, and sunset from 7:45 PM to 8:01 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.85:547:45
213.85:547:45
313.95:547:46
413.95:547:47
513.95:557:48
613.95:557:48
713.95:557:49
813.95:557:50
913.95:557:50
1013.95:557:51
1113.95:557:52
1213.95:567:52
1314.05:567:53
1414.05:567:54
1514.05:577:54
1614.05:577:55
1714.05:577:55
1814.05:587:56
1914.05:587:57
2014.05:587:57
2114.05:597:58
2214.05:597:58
2314.06:007:59
2414.06:007:59
2514.06:017:59
2614.06:018:00
2714.06:028:00
2814.06:028:01
2914.06:038:01
3014.06:048:01
3114.06:048:01

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 7.1 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.48 kWh/m² to a high of 7.1 kWh/m² in December across the year — December's 7.1 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
17.0Intense
27.0Intense
37.0Intense
47.0Intense
57.1Intense
67.1Intense
77.1Intense
87.1Intense
97.1Intense
107.1Intense
117.1Intense
127.1Intense
137.1Intense
147.1Intense
157.1Intense
167.1Intense
177.1Intense
187.1Intense
197.1Intense
207.1Intense
217.1Intense
227.1Intense
237.1Intense
247.1Intense
257.1Intense
267.1Intense
277.1Intense
287.1Intense
297.1Intense
307.1Intense
317.1Intense
Planning a trip in December

Is December a good time to visit San Javier?

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

5.3
Sightseeing
10th-best month of the year
7.2
Beach & pool
2nd-best month of the year

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

What to pack for San Javier in December

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

In December, San Javier sees daytime highs around 30°C and nights near 19°C. Pack light clothes and sun protection. Worth having: rain gear. About 9 days see rain.

light clothessun protectionrain gear

UV index in San Javier in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 13 (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 Javier peaks around January 20 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 — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateHighVery highExtremeJan 20UV 13Jun 19UV 3
UV index (midday)Level
Jan14Extreme
Feb13Extreme
Mar11Extreme
Apr7High
May4Moderate
Jun3Moderate
Jul4Moderate
Aug5High
Sep7Very high
Oct8Very high
Nov11Extreme
Dec13Extreme

Air quality in San Javier 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 Javier is worst in August — around 22 µg/m³ PM2.5 (moderate), about 3.8× the cleanest month (May, 6 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodAug 1721 µg/m³May 116 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb8Good
Mar6Good
Apr6Good
May6Good
Jun7Good
Jul13Moderate
Aug22Moderate
Sep15Moderate
Oct9Good
Nov6Good
Dec7Good
Location & terrain

Where is San Javier?

San Javier sits at 30.6°S, 59.9°W, 30 m above sea level, in Argentina. The nearest listed city is La Paz, 33 km away.

Topography around San Javier

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

Within 3 km, the terrain around San Javier has only modest variations in elevation — a maximum elevation change of 29 m around an average of 22 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 36 m; within 80 km, only modest variations in elevation — a maximum elevation change of 78 m.

The land around San Javier is covered by wetland (50%) and grassland (20%) within 3 km, wetland (71%) within 16 km, and grassland (27%), wetland (26%) and cropland (23%) within 80 km.

3 km
29 m
16 km
36 m
80 km
78 m
treesgrasslandcroplandartificial surfaceswaterwetland
December weather nearby: La Paz 33 km · Santa Elena 43 km · San Justo 68 km · Esquina 74 km · Federal 118 km · Vera 128 km · Esperanza 136 km · Santa Fe 140 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 Javier (-30.5807°, -59.9296°, elevation 30 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).