Rosário do Sul weather in December

In December, Rosário do Sul sees average daytime highs of 30°C and overnight lows near 19°C, with 132 mm of rain across 9.2 wet days and about 13.9 hours of daylight. It is the 2nd-warmest and 5th-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 44% 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 13 h 54 min by month's end. Set against the rest of the year, December is Rosário do Sul's 2nd-clearest and 5th-windiest month. For the whole year in context, see Rosário do Sul's year-round climate.

Daytime high
30°
2nd warmest
Overnight low
19°
10th coldest
Rainfall
132 mm
9.2 wet days
Daylight
13 h 54 min
6:38 AM – 8:34 PM
Cloud cover
50%
2nd clearest
Wind
13 km/h
5th windiest
Solar energy
6.95 kWh/m²
Travel score
5.1
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 Rosário do Sul reaches about 30°C in the afternoon and slips back to 19°C overnight — a 12°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 3°C warmer than November and on par with January.

10°20°30°40°151015202531
Avg high (°C)Avg low (°C)
12917
22917
32918
42918
53018
63018
73018
83018
93018
103018
113018
123018
133018
143018
153019
163019
173019
183019
193019
203019
213119
223119
233119
243119
253119
263120
273120
283120
293120
303120
313120

How December really feels in Rosário do Sul

Once humidity and wind are folded in, December averages 0 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
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

December sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Rosário do Sul 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
Jan31° / 20°13411.513.74.5
Feb30° / 20°12910.313.14.9
Mar29° / 18°122912.25.9
Apr25° / 15°1519.311.37.0
May21° / 12°1148.710.56.7
Jun19° / 10°1309.410.16.1
Jul18° / 1299.410.26.2
Aug21° / 10°1168.610.96.8
Sep22° / 12°1559.911.86.7
Oct25° / 14°1891112.76.7
Nov28° / 16°1298.513.56.5
Dec30° / 19°1329.213.95.1

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 44% 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 43%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15941
25941
35842
45842
55941
65941
75941
85941
95941
105941
115842
125842
135842
145842
155842
165743
175743
185743
195644
205545
215545
225545
235545
245446
255446
265446
275545
285545
295545
305644
315644

Chance of precipitation in December

Any precipitation

Rosário do Sul gets around 132 mm of rain over 9.2 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 30% and peaks near 34% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
128
228
328
428
527
627
727
827
927
1027
1127
1228
1328
1428
1529
1629
1730
1830
1931
2031
2131
2232
2332
2433
2533
2633
2733
2833
2933
3034
3134

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 27% of days. Sticky, muggy-or-worse air turns up on roughly 39% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
11928272150
21928272150
31927272250
41927272250
51927272250
61926272350
71826272360
81826262460
91825262560
101725262560
111724262670
121624262770
131623262780
141523262880
151422262990
161421262990
1713202730100
1813192730110
1912182730121
2012182730131
2111172730151
2211162630161
2310162630171
2410152630181
2510152629191
269142630201
279142529211
289142528222
298142528232
308142528242
318142528242

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

05101520151015202531
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
414light breeze
514light breeze
614light 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 13 h 48 min at the start of December to 13 h 54 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 6:35 AM to 6:45 AM, and sunset from 8:24 PM to 8:41 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.86:358:24
213.86:358:25
313.86:358:25
413.86:358:26
513.96:358:27
613.96:358:27
713.96:358:28
813.96:368:29
913.96:368:30
1013.96:368:30
1113.96:368:31
1213.96:368:32
1313.96:378:32
1413.96:378:33
1513.96:378:33
1613.96:388:34
1713.96:388:35
1813.96:388:35
1914.06:398:36
2014.06:398:36
2114.06:408:37
2214.06:408:37
2314.06:418:38
2414.06:418:38
2514.06:428:39
2613.96:428:39
2713.96:438:39
2813.96:438:40
2913.96:448:40
3013.96:448:40
3113.96:458:41

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 6.95 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.42 kWh/m² to a high of 6.95 kWh/m² in December across the year — December's 6.95 kWh/m² sits near the top of that range.

02468151015202531
Solar energy (kWh/m²)Level
17.0Intense
27.0Intense
37.0Intense
47.0Intense
57.0Intense
67.0Intense
77.0Intense
87.0Intense
97.0Intense
107.0Intense
117.0Intense
127.0Intense
137.0Intense
147.0Intense
157.0Intense
166.9Intense
176.9Intense
186.9Intense
196.9Intense
206.9Intense
216.9Intense
226.9Intense
236.9Intense
246.9Intense
256.9Intense
266.9Intense
276.9Intense
286.9Intense
296.9Intense
306.9Intense
316.9Intense
Planning a trip in December

Is December a good time to visit Rosário do Sul?

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

5.1
Sightseeing
10th-best month of the year
7.1
Beach & pool
3rd-best month of the year

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

What to pack for Rosário do Sul in December

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

In December, Rosário do Sul 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 Rosário do Sul 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 Rosário do Sul peaks around January 18 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 highModerateVery highExtremeJan 18UV 13Jun 19UV 3
UV index (midday)Level
Jan13Extreme
Feb13Extreme
Mar10Very high
Apr7Very high
May4Moderate
Jun3Moderate
Jul4Moderate
Aug5Moderate
Sep7Very high
Oct7Very high
Nov11Extreme
Dec12Extreme
Location & terrain

Where is Rosário do Sul?

Rosário do Sul sits at 30.3°S, 54.9°W, 123 m above sea level, in Brazil. The nearest listed city is São Gabriel, 58 km away.

Topography around Rosário do Sul

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

Within 3 km, the terrain around Rosário do Sul has only modest variations in elevation — a maximum elevation change of 76 m around an average of 102 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 119 m; within 80 km, significant variations in elevation — a maximum elevation change of 306 m.

The land around Rosário do Sul is covered by trees (35%), grassland (25%) and artificial surfaces (20%) within 3 km, grassland (43%) and cropland (38%) within 16 km, and grassland (55%) and cropland (31%) within 80 km.

3 km
76 m
16 km
119 m
80 km
306 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetland
December weather nearby: São Gabriel 58 km · São Francisco de Assis 81 km · Dom Pedrito 84 km · Sant'Ana do Livramento 92 km · Rivera 94 km · Alegrete 100 km · São Pedro do Sul 100 km · Santiago 119 km

Brazil travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / N
127 / 220 V · 60 Hz
Prices
≈ 46% of US
price level, 2025
GDP per capita
$10,713
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
89%
of population, 2024
Homicide rate
19.3
per 100k, 2023
Road deaths
16
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 482
Religion
Roman Catholic 57%Evangelical 27%none 9%other 4%

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 Rosário do Sul (-30.2583°, -54.9142°, elevation 123 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).