Rio do Sul weather in December

In December, Rio do Sul sees average daytime highs of 27°C and overnight lows near 18°C, with 149 mm of rain across 16.5 wet days and about 13.7 hours of daylight. It is the 3rd-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 27°C through the month. The sky is clear or mostly clear about 14% of the time in December, and the air most often feels muggy.

Daylight stretches from about 13 h 36 min at the start of December to 13 h 42 min by month's end. Set against the rest of the year, December is Rio do Sul's 10th-clearest and 4th-windiest month. For the whole year in context, see Rio do Sul's year-round climate.

Daytime high
27°
3rd warmest
Overnight low
18°
9th coldest
Rainfall
149 mm
16.5 wet days
Daylight
13 h 42 min
6:24 AM – 8:06 PM
Cloud cover
73%
10th clearest
Wind
6 km/h
4th windiest
Solar energy
5.6 kWh/m²
Travel score
5.3
out of 10

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 27°C through the month.

A typical December day in Rio do Sul reaches about 27°C in the afternoon and slips back to 18°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 23°C and 31°C. Set against its neighbours, December runs about 2°C warmer than November and about 1°C cooler than January.

10°15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12617
22617
32617
42617
52717
62717
72717
82717
92717
102718
112718
122718
132718
142718
152718
162718
172718
182718
192718
202818
212818
222818
232818
242818
252818
262819
272819
282819
292819
302819
312819

Rio do Sul weather by month

How December compares with the rest of the year at a glance. December is the 3rd-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan28° / 19°18420.413.54.7
Feb28° / 19°15418.3134.8
Mar27° / 18°10515.212.25.6
Apr24° / 15°829.411.46.8
May21° / 12°1059.110.76.5
Jun19° / 10°1119.810.36.0
Jul19° / 991010.56.0
Aug20° / 10°949.6116.4
Sep22° / 13°15112.411.86.0
Oct23° / 15°15015.112.75.7
Nov25° / 16°12114.813.35.8
Dec27° / 18°14916.513.75.3

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 14% 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 71%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13169
23169
33169
43070
53169
63169
73169
83169
93070
103070
113070
123169
133169
143070
153070
162971
172971
182971
192971
202971
212872
222773
232773
242872
252872
262773
272773
282773
292674
302773
312773

Chance of precipitation in December

Any precipitation

Rio do Sul gets around 149 mm of rain over 16.5 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 54% and peaks near 59% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202531
Rain chance (%)
151
251
351
451
551
651
751
852
952
1052
1152
1252
1353
1453
1553
1654
1754
1854
1955
2055
2155
2255
2356
2456
2556
2657
2757
2858
2958
3059
3159

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 41% of days. Sticky, muggy-or-worse air turns up on roughly 50% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
172139321
272039331
361939341
461939352
561839352
661838362
751738372
851737383
951637393
1051637394
1151536404
1241536405
1341435415
1441435426
1541334426
1631333437
1731333438
1831332449
19312314410
20312304410
21212304511
22212294512
23211294513
24211284514
25111274615
26111274615
27111264616
28110264616
29110264617
30110264717
31110254717

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

0246810151015202531
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
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 36 min at the start of December to 13 h 42 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 6:21 AM to 6:31 AM, and sunset from 7:56 PM to 8:13 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.66:217:56
213.66:217:57
313.66:217:58
413.66:217:58
513.66:217:59
613.66:218:00
713.76:218:00
813.76:218:01
913.76:228:02
1013.76:228:02
1113.76:228:03
1213.76:228:04
1313.76:238:04
1413.76:238:05
1513.76:238:05
1613.76:248:06
1713.76:248:07
1813.76:248:07
1913.76:258:08
2013.76:258:08
2113.76:268:09
2213.76:268:09
2313.76:268:10
2413.76:278:10
2513.76:288:10
2613.76:288:11
2713.76:298:11
2813.76:298:12
2913.76:308:12
3013.76:308:12
3113.76:318:13

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 5.6 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 2.5 kWh/m² to a high of 5.6 kWh/m² in December across the year — December's 5.6 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.6Bright
25.5Bright
35.5Bright
45.5Bright
55.5Bright
65.5Bright
75.5Bright
85.5Bright
95.5Bright
105.5Bright
115.6Bright
125.6Bright
135.6Bright
145.6Bright
155.6Bright
165.6Bright
175.6Bright
185.6Bright
195.6Bright
205.6Bright
215.6Bright
225.6Bright
235.6Bright
245.6Bright
255.6Bright
265.6Bright
275.6Bright
285.6Bright
295.6Bright
305.6Bright
315.6Bright
Planning a trip in December

Is December a good time to visit Rio do Sul?

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
5.5
Beach & pool
3rd-best month of the year

December is a reasonable time to visit Rio do Sul for sightseeing.

What to pack for Rio do Sul in December

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

In December, Rio do Sul sees daytime highs around 27°C and nights near 18°C. Pack light clothes and rain gear. Worth having: sun protection. About 17 days see rain.

light clothesrain gearsun protection

UV index in Rio do Sul 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 Rio do Sul peaks around January 19 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 10 at about 5 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighModerateHighVery highExtremeJan 19UV 14Jul 10UV 5
UV index (midday)Level
Jan14Extreme
Feb14Extreme
Mar11Extreme
Apr8Very high
May6High
Jun5Moderate
Jul5Moderate
Aug6High
Sep8Very high
Oct9Very high
Nov12Extreme
Dec13Extreme

Air quality in Rio do Sul 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 Rio do Sul is worst in September — around 15 µg/m³ PM2.5 (moderate), about 1.6× the cleanest month (December, 10 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 915 µg/m³Dec 1710 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb10Good
Mar10Good
Apr11Good
May13Moderate
Jun13Moderate
Jul14Moderate
Aug15Moderate
Sep15Moderate
Oct12Good
Nov10Good
Dec10Good
Location & terrain

Where is Rio do Sul?

Rio do Sul sits at 27.2°S, 49.6°W, 346 m above sea level, in Brazil. The nearest listed city is Presidente Getúlio, 18 km away.

Topography around Rio do Sul

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

Within 3 km, the terrain around Rio do Sul has significant variations in elevation — a maximum elevation change of 353 m around an average of 424 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 703 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,735 m.

The land around Rio do Sul is covered by trees (51%) and artificial surfaces (35%) within 3 km, trees (65%) and grassland (21%) within 16 km, and trees (80%) within 80 km.

3 km
353 m
16 km
703 m
80 km
1,735 m
treesgrasslandcroplandartificial surfaceswater
December weather nearby: Presidente Getúlio 18 km · Ibirama 21 km · Ituporanga 23 km · Pouso Redondo 29 km · Taió 37 km · Indaial 54 km · Otacílio Costa 56 km · Timbó 57 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 Rio do Sul (-27.2142°, -49.6431°, elevation 346 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).