Castelar weather in December

In December, Castelar sees average daytime highs of 28°C and overnight lows near 17°C, with 87 mm of rain across 8.6 wet days and about 14.3 hours of daylight. It is the 3rd-warmest and 6th-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 51% of the time in December, and the air most often feels humid.

Daylight stretches from about 14 h 12 min at the start of December to 14 h 18 min by month's end. Set against the rest of the year, December is Castelar's 2nd-clearest and 5th-windiest month. For the whole year in context, see Castelar's year-round climate.

Daytime high
28°
3rd warmest
Overnight low
17°
10th coldest
Rainfall
87 mm
8.6 wet days
Daylight
14 h 18 min
5:41 AM – 8:00 PM
Cloud cover
43%
2nd clearest
Wind
13 km/h
5th windiest
Solar energy
7.45 kWh/m²
Travel score
6.5
out of 10

Castelar is city in Buenos Aires Province, Argentina.

Density
5,302/km²
people per km²
Founded
1910

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 Castelar reaches about 28°C in the afternoon and slips back to 17°C overnight — a 11°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
52716
62716
72716
82716
92716
102716
112816
122816
132816
142816
152817
162817
172817
182817
192817
202817
212917
222917
232917
242918
252918
262918
272918
282918
292918
302918
312918

Castelar weather by month

How December compares with the rest of the year at a glance. December is the 3rd-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 18°887.714.15.9
Feb28° / 18°938.313.36.4
Mar26° / 16°857.512.37.3
Apr22° / 12°918.111.27.2
May18° / 626.210.26.5
Jun15° / 585.99.75.1
Jul15° / 5769.94.8
Aug17° / 605.910.75.9
Sep19° / 716.811.86.6
Oct22° / 12°1119.312.96.8
Nov25° / 14°928.413.87.2
Dec28° / 17°878.614.36.5

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 51% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 13% of December, with mostly cloudy or overcast conditions the remaining 36%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
16337
26337
36436
46436
56436
66535
76535
86535
96634
106535
116535
126535
136535
146535
156535
166436
176436
186436
196436
206436
216436
226436
236436
246436
256436
266436
276436
286436
296436
306436
316436

Chance of precipitation in December

Any precipitation

Castelar gets around 87 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 29% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
127
227
327
427
527
628
728
828
928
1028
1129
1229
1329
1429
1529
1629
1729
1829
1929
2028
2128
2228
2327
2427
2527
2627
2727
2827
2927
3027
3127

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 30% of days. Sticky, muggy-or-worse air turns up on roughly 17% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
141252770
241252770
341242770
441242871
540242871
640242871
739242881
838242881
938252981
1037252981
1135262991
1234262991
13332630101
14322730102
15302730112
16292731122
17282731132
18262731142
19252631153
20242631173
21232531183
22222530204
23212431214
24202330224
25192230235
26192130245
27182130255
28172030266
29172030276
30162030277
31162030287

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 12 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 6 minutes over December. Sunrise moves from 5:40 AM to 5:49 AM, and sunset from 7:49 PM to 8:07 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.25:407:49
214.25:407:50
314.25:407:51
414.25:407:51
514.25:407:52
614.25:407:53
714.25:407:54
814.25:407:55
914.35:407:55
1014.35:407:56
1114.35:407:57
1214.35:407:57
1314.35:417:58
1414.35:417:59
1514.35:417:59
1614.35:418:00
1714.35:428:01
1814.35:428:01
1914.35:428:02
2014.35:438:02
2114.35:438:03
2214.35:448:03
2314.35:448:04
2414.35:458:04
2514.35:458:05
2614.35:468:05
2714.35:468:05
2814.35:478:06
2914.35:488:06
3014.35:488:06
3114.35:498:07

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 7.45 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.24 kWh/m² to a high of 7.45 kWh/m² in December across the year — December's 7.45 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
87.5Intense
97.5Intense
107.5Intense
117.5Intense
127.5Intense
137.5Intense
147.5Intense
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
307.4Intense
317.4Intense
Planning a trip in December

Is December a good time to visit Castelar?

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

6.5
Sightseeing
6th-best month of the year
7.3
Beach & pool
2nd-best month of the year

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

What to pack for Castelar in December

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

In December, Castelar 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 Castelar 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 24 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 Castelar 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 Castelar peaks around January 13 at about 12 (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 10 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateHighVery highExtremeJan 13UV 12Jun 19UV 3
UV index (midday)Level
Jan13Extreme
Feb11Extreme
Mar9Very high
Apr6High
May3Moderate
Jun3Moderate
Jul3Moderate
Aug4Moderate
Sep6High
Oct8Very high
Nov11Extreme
Dec12Extreme

Air quality in Castelar 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 Castelar is worst in June — around 25 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (December, 12 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateJun 2325 µg/m³Dec 1612 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb14Moderate
Mar16Moderate
Apr17Moderate
May22Moderate
Jun25Moderate
Jul25Moderate
Aug24Moderate
Sep19Moderate
Oct16Moderate
Nov13Moderate
Dec12Moderate
Location & terrain

Where is Castelar?

Castelar sits at 34.7°S, 58.6°W, 25 m above sea level, in Argentina. The nearest listed city is Morón, 2.0 km away.

Topography around Castelar

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

Within 3 km, the terrain around Castelar has only modest variations in elevation — a maximum elevation change of 27 m around an average of 26 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 105 m.

The land around Castelar is covered by artificial surfaces (84%) within 3 km, artificial surfaces (64%) and trees (20%) within 16 km, and grassland (30%) and cropland (25%) within 80 km.

3 km
27 m
16 km
53 m
80 km
105 m
treesgrasslandcroplandartificial surfaceswaterwetland
December weather nearby: Morón 2.0 km · Haedo 5.0 km · El Palomar 5.0 km · San Antonio de Padua 5.0 km · Villa Sarmiento 7.0 km · Hurlingham 7.0 km · Isidro Casanova 7.0 km · San Justo 8.0 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 Castelar (-34.6514°, -58.6407°, elevation 25 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).