Climate and average weather in Rio Claro

In Rio Claro, the weather is humid, hot, wet, and partly cloudy and remarkably steady, with daytime highs holding near hot levels all year. The wettest stretch peaks around January.

Best: late April to late September

Over the course of the year, the temperature in Rio Claro typically varies from 14°C to 29°C, and is rarely below 11°C or above 33°C. February 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 Claro for warm-weather activities is from late April to late September.

Hottest
Feb
29°
Coldest
Jul
14°
Wettest
Jan
295 mm
Driest
Jun
35 mm
Rain / yr
1595 mm
184 wet days
Daylight
10.6–13.4 h
shortest–longest
Elevation
464 m
22.7°S
Clearest
Aug
48% cloud

Rio Claro is Place in Brasil.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Rio Claro 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 late April to late September.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

Temperatures in Rio Claro stay fairly even through the year, without a distinct hot or cool season. The warmest month is February, with an average high of 29°C and low of 21°C; the coolest is July, with an average low of 14°C and high of 23°C.

Days typically run about 8°C warmer than nights year-round.

10°15°20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan2921
Feb2921
Mar2820
Apr2619
May2416
Jun2415
Jul2314
Aug2415
Sep2516
Oct2618
Nov2619
Dec2820

Average hourly temperature in Rio Claro

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 February afternoons, near 29°C, and coldest before dawn in July, near 14°C.

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

Rio Claro 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
Jan29° / 21°2952413.23.8
Feb29° / 21°2042012.83.9
Mar28° / 20°20122.812.24.4
Apr26° / 19°10214.111.55.9
May24° / 16°6310.710.96.8
Jun24° / 15°356.710.67.6
Jul23° / 14°40710.77.6
Aug24° / 15°367.311.27.6
Sep25° / 16°7812.111.96.4
Oct26° / 18°11516.112.55.5
Nov26° / 19°18820.413.14.8
Dec28° / 20°23723.113.44.3

Chance of rain

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

Rio Claro gets about 1595 mm of precipitation a year. On a typical day the chance of rain is very wet, but that rises and falls sharply with the seasons.

The wetter season lasts 5.8 months, from around Oct 16 to Apr 11, peaking in December at about 80% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jun 18.

January is the wettest month by volume, with 295 mm over about 24 wet days; June is the driest, with 35 mm.

0%10%20%30%40%50%60%70%80%90%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetDec 29 · 80%Jun 18 · 20%
Rain on a day (%)Rain days
Jan7724
Feb7220
Mar7223
Apr4814
May3511
Jun227
Jul237
Aug247
Sep4012
Oct5316
Nov6820
Dec7423

Monthly rainfall

Over a full year, Rio Claro collects about 1595 mm of rain across 184 wet days — roughly 133 mm in an average month.

It doesn’t fall evenly. January is the wettest month with 295 mm, while June is the driest at just 35 mm. The three wettest months alone bring about 46% of the year’s total.

050100150200250300350JanFebMarAprMayJunJulAugSepOctNovDec2952042011026335403678115188237
Rainfall (mm)Rain days
Jan29524
Feb20420
Mar20123
Apr10214
May6311
Jun357
Jul407
Aug367
Sep7812
Oct11516
Nov18820
Dec23723

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Rio Claro, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around April 3 and lasts for 5.6 months, ending around September 18. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 58% of the time on average.

The cloudier part of the year begins around September 19 and lasts for 6.4 months, ending around April 2. The cloudiest month is November, when it is overcast or mostly cloudy 78% 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 25 · 59%Dec 4 · 19%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan2773
Feb3466
Mar3763
Apr4753
May4951
Jun5644
Jul5842
Aug5842
Sep4456
Oct2872
Nov2278
Dec2377

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 24 min of light; the shortest, around June 9, only 10 h 36 min — a swing of roughly 2 h 48 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan13.26:287:43
Feb12.86:487:35
Mar12.27:017:11
Apr11.57:136:41
May10.97:256:20
Jun10.67:386:15
Jul10.77:406:24
Aug11.27:246:37
Sep11.96:556:47
Oct12.56:256:58
Nov13.16:087:15
Dec13.46:117:34

Sunny days

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

Rio Claro averages about 8 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 2 and 15 days.

The sunnier stretch runs 5.3 months, from around Apr 15 to Sep 22. The sunniest month is August, with roughly 14 sunny days (mixed).

The greyest month is December, down near 3 sunny days — about 79% fewer than the August peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightAug 2415 daysDec 32 days
Sunny daysSky
Jan4Gloomy
Feb6Gloomy
Mar6Gloomy
Apr8Mixed
May10Mixed
Jun12Mixed
Jul14Mixed
Aug14Mixed
Sep10Mixed
Oct5Gloomy
Nov3Gloomy
Dec3Gloomy

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 Claro, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 7.2 months, from around October 4 to May 9. The muggiest month is January, when the air feels humid, muggy or worse about 100% of the time.

The most comfortable stretch runs from around May 10 to October 3, and July is the most comfortable month — the air is dry or comfortable 78% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJul 17 · 81%Jan 1 · 0%oppressivehumidcomfortablemuggydryhumidcomfortablehumid
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
Jan0075934
Feb0076033
Mar00116523
Apr0730576
May53050150
Jun12483820
Jul22562200
Aug21492910
Sep93644110
Oct31740391
Nov0931545
Dec01146718

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 Claro is steady company: average speeds sit near 5 km/hcalm — in every month of the year, with no meaningful windy or calm season.

0510JanFebMarAprMayJunJulAugSepOctNovDeccalmSep 15 · 6 km/hMar 28 · 4 km/h
Wind speed (km/h)Feels
Jan5calm
Feb5calm
Mar4calm
Apr4calm
May5calm
Jun5calm
Jul5calm
Aug5calm
Sep6calm
Oct6calm
Nov5calm
Dec5calm

Hazard calendar for Rio Claro

In seasonPeak

When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.

Rio Claro's rainy season runs November–March, when most of the year's rain falls.

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

Best time to visit Rio Claro

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around mid September, Rio Claro 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 Claro for general outdoor tourist activities is from late April to late September, with a peak score in the third week of June.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationJun 18 · 7.7

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
Jan3.8fair
Feb3.9fair
Mar4.4fair
Apr5.9good
May6.8good
Jun7.6ideal
Jul7.6ideal
Aug7.5ideal
Sep6.4good
Oct5.5good
Nov4.8fair
Dec4.3fair

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 Claro for hot-weather activities is from early April to late October, with a peak score in the last week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 23 · 6.6

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 Claro, 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.

Rio Claro packs about the same all year — highs hold near 29°C. Across the year the things worth having are light clothes, rain gear and sun protection.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In February, Rio Claro sees daytime highs around 29°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 20 days see rain.

Sea temperature near Rio Claro

Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.

The sea at the nearest coast (about 51 km away) is warmest in February at about 27°C and coldest in August near 21°C.

The water stays above 20°C all year — warm enough for a swim any month.

20°22°24°26°28°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan27Warm
Feb27Warm
Mar27Warm
Apr26Warm
May24Warm
Jun23Refreshing
Jul22Refreshing
Aug21Refreshing
Sep22Refreshing
Oct23Refreshing
Nov23Refreshing
Dec25Warm

UV index (midday) in Rio Claro 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 Claro peaks around February 9 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 12 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 highExtremeFeb 9UV 14Jul 12UV 5
UV index (midday)Level
Jan14Extreme
Feb14Extreme
Mar12Extreme
Apr9Very high
May7High
Jun6High
Jul5High
Aug8Very high
Sep7High
Oct11Extreme
Nov13Extreme
Dec14Extreme

Average hourly UV index in Rio Claro

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 February the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 6.5 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
Apr74.5
May5.52.5
Jun50
Jul50
Aug6.53.5
Sep6.53
Oct85.5
Nov8.56.5
Dec97

Air quality in Rio Claro 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 Claro is worst in September — around 33 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (December, 15 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateSep 1332 µg/m³Dec 2115 µg/m³
PM2.5 (µg/m³)Level
Jan16Moderate
Feb16Moderate
Mar17Moderate
Apr19Moderate
May24Moderate
Jun29Moderate
Jul31Moderate
Aug27Moderate
Sep33Moderate
Oct20Moderate
Nov17Moderate
Dec15Moderate
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Rio Claro 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
Jul1000
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 Claro banks about 4,313 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around February.

01,0002,0003,0004,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan451
Feb412
Mar431
Apr374
May313
Jun276
Jul271
Aug294
Sep320
Oct369
Nov375
Dec428

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 Claro receives about 4.6 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.4 and 5.7 kWh/m².

The brighter stretch of the year lasts 6.2 months, from around Sep 22 to Mar 28. The brightest month is February, averaging about 5.6 kWh/m² (bright).

The dimmest month is May, down near 3.6 kWh/m² — roughly 36% less than the February peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecbrighterdimmerbrighterdimmoderatebrightintenseFeb 65.7 kWhMay 313.4 kWh
Solar energy (kWh/m²)Level
Jan5.5Bright
Feb5.7Bright
Mar4.9Bright
Apr4.3Bright
May3.6Moderate
Jun3.4Moderate
Jul3.5Moderate
Aug4.3Bright
Sep4.6Bright
Oct5.0Bright
Nov5.1Bright
Dec5.5Bright

Where is Rio Claro?

Rio Claro sits at 22.7°S, 44.1°W, 464 m above sea level, in Brazil. The nearest listed city is Barra Mansa, 20 km away.

Topography around Rio Claro

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

Within 3 km, the terrain around Rio Claro has large variations in elevation — a maximum elevation change of 814 m around an average of 583 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,265 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,761 m.

The land around Rio Claro is covered by trees (50%) and grassland (48%) within 3 km, grassland (56%) and trees (43%) within 16 km, and trees (43%), grassland (29%) and water (24%) within 80 km.

3 km
814 m
16 km
1,265 m
80 km
2,761 m
treesgrasslandartificial surfaceswater
Nearby: Barra Mansa 20 km · Volta Redonda 22 km · Piraí 27 km · Pinheiral 27 km · Mangaratiba 28 km · Angra dos Reis 37 km · Porto Real 37 km · Itaguaí 40 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 Claro (-22.7231°, -44.1356°, elevation 464 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).