Santa Rosa weather in December

In December, Santa Rosa sees average daytime highs of 31°C and overnight lows near 21°C, with 218 mm of rain across 15.4 wet days and about 13.4 hours of daylight. It is the 1st-warmest and 4th-wettest month of the year here.

Day-to-day highs hold fairly steady near 31°C through the month. The sky is clear or mostly clear about 18% of the time in December, and the air most often feels muggy.

Daylight stretches from about 13 h 18 min at the start of December to 13 h 24 min by month's end. Set against the rest of the year, December is Santa Rosa's 9th-clearest and 5th-windiest month. For the whole year in context, see Santa Rosa's year-round climate.

Daytime high
31°
1st warmest
Overnight low
21°
11th coldest
Rainfall
218 mm
15.4 wet days
Daylight
13 h 24 min
6:31 AM – 7:57 PM
Cloud cover
69%
9th clearest
Wind
6 km/h
5th windiest
Solar energy
5.68 kWh/m²
Travel score
3.7
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 31°C through the month.

A typical December day in Santa Rosa reaches about 31°C in the afternoon and slips back to 21°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 37°C. Set against its neighbours, December runs on par with November and on par with January.

15°20°25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13120
23120
33120
43121
53121
63121
73121
83121
93121
103121
113121
123121
133121
143121
153121
163121
173221
183221
193221
203221
213221
223221
233221
243222
253222
263222
273222
283222
293222
303222
313222

How December really feels in Santa Rosa

Once humidity and wind are folded in, December averages 24 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
24
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.

Santa Rosa weather by month

How December compares with the rest of the year at a glance. December is the 1st-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 22°22416.513.33.7
Feb30° / 21°22816.212.84.1
Mar28° / 20°24918.112.24.8
Apr25° / 17°16215.311.55.9
May22° / 14°7911.910.96.3
Jun20° / 11°387.910.66.6
Jul21° / 235.110.77.5
Aug25° / 11°163.611.28.3
Sep28° / 15°224.311.97.1
Oct30° / 18°819.512.55.0
Nov31° / 20°12611.913.14.3
Dec31° / 21°21815.413.43.7

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 18% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 16% of December, with mostly cloudy or overcast conditions the remaining 66%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13466
23466
33367
43268
53268
63268
73268
83268
93268
103268
113367
123367
133466
143565
153565
163565
173565
183664
193664
203664
213664
223565
233565
243565
253565
263466
273565
283466
293565
303565
313565

Chance of precipitation in December

Any precipitation

Santa Rosa gets around 218 mm of rain over 15.4 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 49% and peaks near 51% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
150
250
351
451
551
651
751
851
951
1051
1150
1250
1350
1449
1549
1648
1748
1847
1947
2047
2147
2247
2348
2448
2548
2649
2749
2849
2949
3049
3150

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 40% of days. Sticky, muggy-or-worse air turns up on roughly 71% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
15142440160
24142441170
34132341180
43122342190
53122342200
63112242210
73102242230
83102241241
9392241251
10382241261
11382241261
12372241271
13372141281
14362141281
15362141291
16362140301
17362040311
18362039321
19361939331
20361838341
21361738351
22361738361
23361638371
24361538381
25361438391
26261338401
27261338411
28251237421
29251237431
30151236441
31151236451

Wind in December

Winds average 6 km/h in December.

Across December, daily wind ranges from about 6 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 13 h 18 min at the start of December to 13 h 24 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 6:27 AM to 6:38 AM, and sunset from 7:48 PM to 8:04 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.36:277:48
213.36:277:48
313.46:287:49
413.46:287:50
513.46:287:50
613.46:287:51
713.46:287:51
813.46:287:52
913.46:297:53
1013.46:297:53
1113.46:297:54
1213.46:307:55
1313.46:307:55
1413.46:307:56
1513.46:317:56
1613.46:317:57
1713.46:317:57
1813.46:327:58
1913.46:327:58
2013.46:337:59
2113.46:337:59
2213.46:338:00
2313.46:348:00
2413.46:348:01
2513.46:358:01
2613.46:358:02
2713.46:368:02
2813.46:368:02
2913.46:378:03
3013.46:388:03
3113.46:388:04

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 5.68 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.94 kWh/m² to a high of 5.68 kWh/m² in December across the year — December's 5.68 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.5Bright
25.4Bright
35.4Bright
45.4Bright
55.4Bright
65.4Bright
75.4Bright
85.4Bright
95.5Bright
105.5Bright
115.5Bright
125.5Bright
135.6Bright
145.6Bright
155.7Bright
165.7Bright
175.7Bright
185.8Bright
195.8Bright
205.8Bright
215.8Bright
225.8Bright
235.9Bright
245.9Bright
255.9Bright
265.9Bright
275.9Bright
285.9Bright
295.9Bright
305.9Bright
315.9Bright
Planning a trip in December

Hazard calendar for Santa Rosa

In seasonPeak

In December, Santa Rosa sits inside its monsoon season. The full year is below, with each hazard's peak months called out.

Santa Rosa's monsoon runs November–April, when most of the year's rain falls.

Monsoon
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit Santa Rosa?

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

3.7
Sightseeing
11th-best month of the year
5.7
Beach & pool
5th-best month of the year

December is a weaker month for outdoor sightseeing in Santa Rosa.

What to pack for Santa Rosa in December

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

In December, Santa Rosa sees daytime highs around 31°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 15 days see rain.

light clothesrain gearsun protection

UV index in Santa Rosa in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 14 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Santa Rosa peaks around January 18 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 11 at about 5 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeJan 18UV 15Jul 11UV 5
UV index (midday)Level
Jan15Extreme
Feb14Extreme
Mar13Extreme
Apr9Very high
May7High
Jun6High
Jul5High
Aug8Very high
Sep10Very high
Oct8Very high
Nov13Extreme
Dec14Extreme

Air quality in Santa Rosa 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 Santa Rosa is worst in September — around 36 µg/m³ PM2.5 (poor), about 8.2× the cleanest month (May, 4 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateModerateSep 2135 µg/m³May 135 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb8Good
Mar7Good
Apr5Good
May4Good
Jun7Good
Jul8Good
Aug15Moderate
Sep36Poor
Oct32Moderate
Nov27Moderate
Dec17Moderate
Location & terrain

Where is Santa Rosa?

Santa Rosa sits at 23.4°S, 64.4°W, 341 m above sea level, in Argentina. The nearest listed city is Pichanal, 23 km away.

Topography around Santa Rosa

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

Within 3 km, the terrain around Santa Rosa has only modest variations in elevation — a maximum elevation change of 78 m around an average of 352 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 433 m; within 80 km, extreme variations in elevation — a maximum elevation change of 4,850 m.

The land around Santa Rosa is covered by cropland (43%) and trees (31%) within 3 km, trees (62%) and cropland (31%) within 16 km, and trees (64%) within 80 km.

3 km
78 m
16 km
433 m
80 km
4,850 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Pichanal 23 km · San Ramón de la Nueva Orán 30 km · Embarcación 39 km · Libertador General San Martín 60 km · Bermejo 74 km · San Pedro de Jujuy 103 km · General Mosconi 109 km · Tartagal 116 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 Santa Rosa (-23.3943°, -64.4251°, elevation 341 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).