Climate and average weather in Cacoal

In Cacoal, the weather is sweltering, wet, and mostly clear and remarkably steady, with daytime highs holding near sweltering levels all year. The wettest stretch peaks around January.

Best: early May to early August

Over the course of the year, the temperature in Cacoal typically varies from 20°C to 33°C, and is rarely below 17°C or above 36°C. August is the hottest month of the year, while February is the coldest.

Based on the travel score, the best time of year to visit Cacoal for warm-weather activities is from early May to early August.

Hottest
Aug
33°
Coldest
Feb
22°
Wettest
Jan
308 mm
Driest
Jul
11 mm
Rain / yr
1925 mm
219 wet days
Daylight
11.3–12.7 h
shortest–longest
Elevation
197 m
11.4°S
Clearest
Jul
28% cloud

Cacoal 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 early May to early August.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

Temperatures in Cacoal stay fairly even through the year, without a distinct hot or cool season. The warmest month is August, with an average high of 33°C and low of 21°C; the coolest is February, with an average low of 22°C and high of 29°C.

Days typically run about 9°C warmer than nights, with the widest day–night swing (around 13°C) in August.

15°20°25°30°35°40°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan2922
Feb2922
Mar3022
Apr3022
May3021
Jun3120
Jul3220
Aug3321
Sep3322
Oct3223
Nov3123
Dec3023

How hot and cold Cacoal really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the hottest afternoons, once humidity is folded in, Cacoal feels like about 37°C (around October 8). Nearly every day a year carries some heat stress, peaking in October.

15°20°25°30°35°40°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan33292222
Feb33292222
Mar34302222
Apr34302222
May33302121
Jun33312020
Jul32322020
Aug34332121
Sep36332222
Oct36322323
Nov35312323
Dec34302323

Average hourly temperature in Cacoal

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 August afternoons, near 33°C, and coldest before dawn in February, near 22°C.

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

Cacoal 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° / 22°30829.312.62.8
Feb29° / 22°29726.412.42.8
Mar30° / 22°27028.212.12.9
Apr30° / 22°15122.311.83.4
May30° / 21°7713.411.54.7
Jun31° / 20°173.511.35.5
Jul32° / 20°112.111.45.1
Aug33° / 21°264.811.64.0
Sep33° / 22°9014.211.93.1
Oct32° / 23°15721.812.32.8
Nov31° / 23°2392512.52.8
Dec30° / 23°28427.912.72.9

Chance of rain

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

Cacoal gets about 1925 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 7.0 months, from around Sep 27 to Apr 26, peaking in February at about 95% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jul 18.

January is the wettest month by volume, with 308 mm over about 29 wet days; July is the driest, with 11 mm.

0%10%20%30%40%50%60%70%80%90%100%110%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetFeb 9 · 95%Jul 18 · 5%
Rain on a day (%)Rain days
Jan9429
Feb9426
Mar9128
Apr7322
May4313
Jun134
Jul72
Aug165
Sep4714
Oct7022
Nov8325
Dec9028

Monthly rainfall

Over a full year, Cacoal collects about 1925 mm of rain across 219 wet days — roughly 160 mm in an average month.

It doesn’t fall evenly. January is the wettest month with 308 mm, while July is the driest at just 11 mm. The three wettest months alone bring about 46% of the year’s total.

050100150200250300350JanFebMarAprMayJunJulAugSepOctNovDec3082972701517717112690157239284
Rainfall (mm)Rain days
Jan30829
Feb29726
Mar27028
Apr15122
May7713
Jun174
Jul112
Aug265
Sep9014
Oct15722
Nov23925
Dec28428

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Cacoal, 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 May 12 and lasts for 5.0 months, ending around October 11. The clearest month is July, when the sky is clear, mostly clear, or partly cloudy 86% of the time on average.

The cloudier part of the year begins around October 12 and lasts for 7.0 months, ending around May 11. The cloudiest month is February, when it is overcast or mostly cloudy 94% 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 1 · 87%Feb 17 · 5%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan793
Feb694
Mar892
Apr2278
May4555
Jun7624
Jul8614
Aug8317
Sep6337
Oct3466
Nov1486
Dec991

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 12 h 42 min of light; the shortest, around June 9, only 11 h 18 min — a swing of roughly 1 h 24 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan12.65:576:33
Feb12.46:096:32
Mar12.16:136:18
Apr11.86:145:58
May11.56:185:46
Jun11.36:265:46
Jul11.46:305:53
Aug11.66:215:58
Sep11.96:025:58
Oct12.35:435:59
Nov12.55:356:07
Dec12.75:426:22

Sunny days

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

Cacoal averages about 8 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 0 and 23 days.

The sunnier stretch runs 4.3 months, from around May 18 to Sep 26. The sunniest month is July, with roughly 23 sunny days (bright).

The greyest month is March, down near 0 sunny days — about 98% fewer than the July peak.

051015202530JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightbrilliantJul 1923 daysMar 30 days
Sunny daysSky
Jan0Gloomy
Feb0Gloomy
Mar0Gloomy
Apr2Gloomy
May8Gloomy
Jun17Bright
Jul23Bright
Aug21Bright
Sep11Mixed
Oct4Gloomy
Nov1Gloomy
Dec1Gloomy

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

The more humid part of the year lasts 9.1 months, from around September 14 to June 17. 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 June 18 to September 13, and August is the most comfortable month — the air is dry or comfortable 27% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecAug 1 · 37%Jan 1 · 0%miserableoppressivemuggyhumidcomfortablehumidcomfortablehumid
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan0000937
Feb0000919
Mar00008910
Apr01248410
May02616733
Jun141943330
Jul519402880
Aug6203025190
Sep14927580
Oct0017902
Nov0002917
Dec0001945

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

0510JanFebMarAprMayJunJulAugSepOctNovDeccalmJul 23 · 7 km/hMar 14 · 5 km/h
Wind speed (km/h)Feels
Jan5calm
Feb5calm
Mar5calm
Apr5calm
May5calm
Jun6calm
Jul7calm
Aug7calm
Sep6calm
Oct5calm
Nov5calm
Dec5calm

Hazard calendar for Cacoal

In seasonPeak

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

Cacoal's monsoon runs October–April, when most of the year's rain falls.

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

Best time to visit Cacoal

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around late July, Cacoal 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 Cacoal for general outdoor tourist activities is from mid May to early August, with a peak score in the second week of June.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationJun 13 · 5.5

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
Jan2.8poor
Feb2.8poor
Mar2.9poor
Apr3.5poor
May4.7fair
Jun5.4fair
Jul5.1fair
Aug4.0fair
Sep3.1poor
Oct2.8poor
Nov2.8poor
Dec2.9poor

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 Cacoal for hot-weather activities is from late May to late August, with a peak score in the second week of July.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 13 · 8.2

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 Cacoal, 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.

Cacoal packs about the same all year — highs hold near 33°C. Across the year the things worth having are light clothes, sun protection and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In August, Cacoal sees daytime highs around 33°C and nights near 21°C. Pack light clothes. Worth having: sun protection. About 5 days see rain.

UV index (midday) in Cacoal 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 Cacoal peaks around January 22 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near September 14 at about 4 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateExtremeJan 22UV 15Sep 14UV 4
UV index (midday)Level
Jan15Extreme
Feb15Extreme
Mar15Extreme
Apr13Extreme
May10Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep3Moderate
Oct11Extreme
Nov14Extreme
Dec14Extreme

Average hourly UV index in Cacoal

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
Feb8.57
Mar8.56.5
Apr86
May75
Jun6.54.5
Jul6.54
Aug6.53.5
Sep40
Oct7.55.5
Nov8.56.5
Dec8.56.5

Air quality in Cacoal 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 Cacoal is worst in September — around 53 µg/m³ PM2.5 (poor), about 6.8× the cleanest month (July, 8 µg/m³).

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

0204060JanFebMarAprMayJunJulAugSepOctNovDecGoodModeratePoorModerateSep 1550 µg/m³Jul 98 µg/m³
PM2.5 (µg/m³)Level
Jan12Good
Feb12Good
Mar12Good
Apr10Good
May9Good
Jun8Good
Jul8Good
Aug31Moderate
Sep53Poor
Oct21Moderate
Nov15Moderate
Dec13Moderate
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Cacoal 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. Cacoal banks about 5,943 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around September.

02,0004,0006,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan494
Feb444
Mar497
Apr481
May481
Jun464
Jul489
Aug524
Sep530
Oct538
Nov499
Dec501

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.

Cacoal receives about 5.1 kWh/m² a day of solar energy — bright — and it stays remarkably steady, holding between 4.5 and 5.9 kWh/m² all year. For solar panels, output here is a flat line, not a seasonal wave.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmoderatebrightintenseOct 85.9 kWhMay 234.5 kWh
Solar energy (kWh/m²)Level
Jan4.9Bright
Feb4.6Bright
Mar4.8Bright
Apr4.7Bright
May4.6Bright
Jun4.7Bright
Jul5.1Bright
Aug5.5Bright
Sep5.8Bright
Oct5.9Bright
Nov5.4Bright
Dec5.0Bright

Where is Cacoal?

Cacoal sits at 11.4°S, 61.4°W, 197 m above sea level, in Brazil. The nearest listed city is Pimenta Bueno, 38 km away.

Topography around Cacoal

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

Within 3 km, the terrain around Cacoal has only modest variations in elevation — a maximum elevation change of 80 m around an average of 189 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 262 m; within 80 km, significant variations in elevation — a maximum elevation change of 434 m.

The land around Cacoal is covered by artificial surfaces (45%), trees (27%) and grassland (25%) within 3 km, grassland (68%) and trees (27%) within 16 km, and grassland (60%) and trees (39%) within 80 km.

3 km
80 m
16 km
262 m
80 km
434 m
treesgrasslandcroplandartificial surfaceswater
Nearby: Pimenta Bueno 38 km · Espigão dOeste 48 km · Rolim de Moura 56 km · Presidente Médici 58 km · Alta Floresta d'Oeste 81 km · Ji Paraná 83 km · Ouro Preto do Oeste 114 km · São Miguel do Guaporé 141 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 Cacoal (-11.4386°, -61.4472°, elevation 197 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).