Climate and average weather in Rio do Sul

In Rio do Sul, the summers are humid, warm, wet, and mostly cloudy and the winters are mild and partly cloudy.

Best: mid March to early December

Over the course of the year, the temperature in Rio do Sul typically varies from 9°C to 28°C, and is rarely below 3°C or above 32°C. January is the hottest month of the year, while July is the coldest.

Based on the travel score, the best time of year to visit Rio do Sul for warm-weather activities is from mid March to early December.

Hottest
Jan
28°
Coldest
Jul
Wettest
Jan
184 mm
Driest
Apr
82 mm
Rain / yr
1504 mm
161 wet days
Daylight
10.3–13.7 h
shortest–longest
Elevation
346 m
27.2°S
Clearest
Aug
61% cloud

Rio do Sul weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around mid March to early December.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Rio do Sul, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 4.2 months, from November 22 to March 29, with daily high temperatures above 26°C. The hottest month of the year in Rio do Sul is January, with an average high of 28°C and low of 19°C.

The cool season lasts 3.0 months, from May 18 to August 17, with daily high temperatures below 20°C. The coldest month of the year in Rio do Sul is July, with an average low of 9°C and high of 19°C.

Days typically run about 9°C warmer than nights year-round.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan2819
Feb2819
Mar2718
Apr2415
May2112
Jun1910
Jul199
Aug2010
Sep2213
Oct2315
Nov2516
Dec2718

Average hourly temperature in Rio do Sul

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on January afternoons, near 28°C, and coldest before dawn in July, near C.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Rio do Sul weather by month

Every month at a glance. Click a month for its detailed page.

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

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Rio do Sul gets about 1504 mm of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.

The wetter season lasts 6.1 months, from around Sep 20 to Mar 24, peaking in January at about 67% chance on a given day. The drier stretch runs the rest of the year, bottoming out around May 1.

January is the wettest month by volume, with 184 mm over about 20 wet days; April is the driest, with 82 mm.

0%10%20%30%40%50%60%70%80%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetJan 23 · 67%May 1 · 27%
Rain on a day (%)Rain days
Jan6520
Feb6518
Mar5015
Apr329
May299
Jun3210
Jul3310
Aug3110
Sep4112
Oct4915
Nov4915
Dec5417

Monthly rainfall

Over a full year, Rio do Sul collects about 1504 mm of rain across 161 wet days — roughly 125 mm in an average month.

It doesn’t fall evenly. January is the wettest month with 184 mm, while April is the driest at just 82 mm. The three wettest months alone bring about 33% of the year’s total.

050100150200JanFebMarAprMayJunJulAugSepOctNovDec184154105821051119994151150121149
Rainfall (mm)Rain days
Jan18420
Feb15418
Mar10515
Apr829
May1059
Jun11110
Jul9910
Aug9410
Sep15112
Oct15015
Nov12115
Dec14917

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Rio do Sul, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.

The clearer part of the year begins around March 31 and lasts for 5.4 months, ending around September 11. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 44% of the time on average.

The cloudier part of the year begins around September 12 and lasts for 6.6 months, ending around March 30. The cloudiest month is October, when it is overcast or mostly cloudy 77% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecAug 26 · 46%Oct 13 · 21%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan2674
Feb2872
Mar3268
Apr3763
May4060
Jun4060
Jul4357
Aug4456
Sep3367
Oct2377
Nov3070
Dec2971

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around January 1, brings about 13 h 42 min of light; the shortest, around June 8, only 10 h 18 min — a swing of roughly 3 h 24 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan13.56:428:14
Feb13.07:048:02
Mar12.27:227:34
Apr11.47:386:59
May10.77:556:35
Jun10.38:106:28
Jul10.58:116:37
Aug11.07:526:54
Sep11.87:187:08
Oct12.76:447:23
Nov13.36:237:45
Dec13.76:248:06

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Rio do Sul averages about 6 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 3 and 10 days.

The sunnier stretch runs 5.3 months, from around Apr 8 to Sep 16. The sunniest month is August, with roughly 9 sunny days (mixed).

The greyest month is February, down near 3 sunny days — about 72% fewer than the August peak.

051015JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedAug 2610 daysFeb 193 days
Sunny daysSky
Jan3Gloomy
Feb2Gloomy
Mar4Gloomy
Apr6Gloomy
May7Gloomy
Jun7Gloomy
Jul9Mixed
Aug10Mixed
Sep6Gloomy
Oct4Gloomy
Nov5Gloomy
Dec4Gloomy

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Rio do Sul, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 6.2 months, from around October 16 to April 23. The muggiest month is January, when the air feels humid, muggy or worse about 93% of the time.

The most comfortable stretch runs from around April 24 to October 15, and July is the most comfortable month — the air is dry or comfortable 97% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJul 17 · 98%Jan 29 · 5%oppressivecomfortablemuggyhumiddryhumidcomfortablehumid
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
Jan16255316
Feb06215517
Mar21233485
Apr162535241
May43342120
Jun5636900
Jul6235300
Aug5139900
Sep37372420
Oct223135120
Nov132736231
Dec41433418

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Wind in Rio do Sul is steady company: average speeds sit near 6 km/hcalm — in every month of the year, with no meaningful windy or calm season.

0510JanFebMarAprMayJunJulAugSepOctNovDeccalmNov 12 · 7 km/hJun 17 · 5 km/h
Wind speed (km/h)Feels
Jan6calm
Feb6calm
Mar5calm
Apr6calm
May6calm
Jun5calm
Jul5calm
Aug6calm
Sep7calm
Oct7calm
Nov7calm
Dec6calm

Best time to visit Rio do Sul

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Rio do Sul throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around late November, Rio do Sul is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit Rio do Sul for general outdoor tourist activities is from mid March to early December, with a peak score in the last week of April.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationApr 23 · 6.9

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan4.7fair
Feb4.8fair
Mar5.6good
Apr6.7good
May6.5good
Jun6.0good
Jul6.0good
Aug6.4good
Sep6.0good
Oct5.7good
Nov5.8good
Dec5.3fair

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Rio do Sul for hot-weather activities is from late October to early May, with a peak score in the second week of April.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timebeach/pool scoretemperaturecloudsprecipitationApr 11 · 6.0

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Rio do Sul, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around January (highs near 28°C), the essentials are light clothes, rain gear and sun protection. In the cold season around July (highs near 19°C), pack rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In January, Rio do Sul sees daytime highs around 28°C and nights near 19°C. Pack light clothes and rain gear. Worth having: sun protection. About 20 days see rain.

UV index (midday) in Rio do Sul by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

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

Average hourly UV index in Rio do Sul

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in January the burn window is concentrated in the middle of the day: about 9 hours a day reach index 3 (protection recommended), and 7 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan97
Feb8.56.5
Mar85.5
Apr6.54
May5.50
Jun4.50
Jul4.50
Aug5.50
Sep74
Oct7.55
Nov8.56.5
Dec97

Air quality in Rio do Sul by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly 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
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Rio do Sul is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecfrost-free year round
Frost-free chance (%)Frost nights
Jan1000
Feb1000
Mar1000
Apr1000
May1000
Jun1000
Jul990
Aug1000
Sep1000
Oct1000
Nov1000
Dec1000

Growing degree days

Degree days (base 10°C)Frost-free shaded

Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Rio do Sul banks about 3,267 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around January.

01,0002,0003,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan414
Feb372
Mar381
Apr293
May194
Jun134
Jul120
Aug167
Sep211
Oct276
Nov318
Dec387

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Rio do Sul receives about 4.1 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 2.4 and 5.6 kWh/m².

The brighter stretch of the year lasts 5.6 months, from around Oct 11 to Mar 29. The brightest month is December, averaging about 5.6 kWh/m² (bright).

The dimmest month is June, down near 2.5 kWh/m² — roughly 55% less than the December peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecbrighterdimmerbrighterdimmoderatebrightintenseDec 265.6 kWhJun 232.4 kWh
Solar energy (kWh/m²)Level
Jan5.5Bright
Feb5.1Bright
Mar4.5Bright
Apr3.7Moderate
May2.9Moderate
Jun2.5Moderate
Jul2.8Moderate
Aug3.5Moderate
Sep3.8Moderate
Oct4.3Bright
Nov5.3Bright
Dec5.6Bright

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
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).