Climate and average weather in Porto Acre

In Porto Acre, the weather is muggy, sweltering, wet, and partly cloudy and remarkably steady, with daytime highs holding near sweltering levels all year. The wettest stretch peaks around March.

Best: late May to early August

Over the course of the year, the temperature in Porto Acre typically varies from 20°C to 33°C, and is rarely below 16°C or above 36°C. September is the hottest month of the year, while May is the coldest.

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

Hottest
Sep
33°
Coldest
May
22°
Wettest
Mar
282 mm
Driest
Jul
26 mm
Rain / yr
1940 mm
230 wet days
Daylight
11.4–12.6 h
shortest–longest
Elevation
121 m
9.6°S
Clearest
Jul
39% cloud

Porto Acre 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 May to early August.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

Temperatures in Porto Acre stay fairly even through the year, without a distinct hot or cool season. The warmest month is September, with an average high of 33°C and low of 22°C; the coolest is May, with an average low of 22°C and high of 30°C.

Days typically run about 9°C warmer than nights, with the widest day–night swing (around 12°C) in August.

15°20°25°30°35°40°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan3023
Feb3023
Mar3023
Apr3022
May3022
Jun3021
Jul3120
Aug3321
Sep3322
Oct3223
Nov3123
Dec3123

How hot and cold Porto Acre 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, Porto Acre feels like about 38°C (around October 12). Nearly every day a year carries some heat stress, peaking in October.

15°20°25°30°35°40°JanFebMarAprMayJunJulAugSepOctNovDecdangerous heat
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan35302323
Feb35302323
Mar35302323
Apr35302222
May34302222
Jun33302121
Jul33312020
Aug35332121
Sep37332222
Oct37322323
Nov37312323
Dec36312323

Average hourly temperature in Porto Acre

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 September afternoons, near 33°C, and coldest before dawn in May, near 22°C.

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

Porto Acre 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
Jan30° / 23°26427.612.52.7
Feb30° / 23°26925.412.32.7
Mar30° / 23°2822812.12.7
Apr30° / 22°18924.811.83.0
May30° / 22°10217.511.64.1
Jun30° / 21°418.611.55.0
Jul31° / 20°26511.55.0
Aug33° / 21°477.511.73.9
Sep33° / 22°9013.411.93.1
Oct32° / 23°15220.712.22.8
Nov31° / 23°21323.812.42.7
Dec31° / 23°26627.312.52.7

Chance of rain

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

Porto Acre gets about 1940 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 6.8 months, from around Oct 13 to May 7, peaking in February at about 91% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jul 22.

March is the wettest month by volume, with 282 mm over about 28 wet days; July is the driest, with 26 mm.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetFeb 14 · 91%Jul 22 · 13%
Rain on a day (%)Rain days
Jan8928
Feb9025
Mar9028
Apr8125
May5618
Jun309
Jul165
Aug258
Sep4513
Oct6621
Nov8024
Dec8827

Monthly rainfall

Over a full year, Porto Acre collects about 1940 mm of rain across 230 wet days — roughly 162 mm in an average month.

It doesn’t fall evenly. March is the wettest month with 282 mm, while July is the driest at just 26 mm. The three wettest months alone bring about 42% of the year’s total.

050100150200250300JanFebMarAprMayJunJulAugSepOctNovDec26426928218910241264790152213266
Rainfall (mm)Rain days
Jan26428
Feb26925
Mar28228
Apr18925
May10218
Jun419
Jul265
Aug478
Sep9013
Oct15221
Nov21324
Dec26627

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Porto Acre, 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 19 and lasts for 4.7 months, ending around October 8. The clearest month is July, when the sky is clear, mostly clear, or partly cloudy 79% of the time on average.

The cloudier part of the year begins around October 9 and lasts for 7.3 months, ending around May 18. The cloudiest month is February, when it is overcast or mostly cloudy 96% 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%JanFebMarAprMayJunJulAugSepOctNovDecJul 27 · 81%Feb 10 · 4%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan595
Feb496
Mar496
Apr1288
May3070
Jun6238
Jul7921
Aug7426
Sep5050
Oct2476
Nov1189
Dec892

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 36 min of light; the shortest, around June 13, only 11 h 24 min — a swing of roughly 1 h 12 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan12.55:245:55
Feb12.35:355:54
Mar12.15:385:42
Apr11.85:375:24
May11.65:405:13
Jun11.55:475:14
Jul11.55:515:20
Aug11.75:445:25
Sep11.95:265:23
Oct12.25:095:22
Nov12.45:025:29
Dec12.55:105:43

Sunny days

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

Porto Acre averages about 5 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 0 and 19 days.

The sunnier stretch runs 4.1 months, from around May 27 to Sep 27. The sunniest month is July, with roughly 18 sunny days (bright).

The greyest month is February, down near 0 sunny days — about 99% fewer than the July peak.

0510152025JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightbrilliantJul 2919 daysFeb 90 days
Sunny daysSky
Jan0Gloomy
Feb0Gloomy
Mar0Gloomy
Apr1Gloomy
May4Gloomy
Jun11Mixed
Jul18Bright
Aug17Bright
Sep8Mixed
Oct3Gloomy
Nov1Gloomy
Dec0Gloomy

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.

Porto Acre is humid all year round — on a typical day the air feels at least humid, and there is no real dry season to wait for.

The stickiest month is January, when it feels muggy, oppressive or miserable about 100% of the time. Even in July, the mildest month, the air is dry or comfortable only 8% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJul 23 · 9%Jan 1 · 0%miserableoppressivemuggyhumidhumidcomfortablehumid
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan00007228
Feb00006733
Mar00006337
Apr00145539
May014125826
Jun12619685
Jul351232480
Aug341326521
Sep12411775
Oct00037621
Nov00016137
Dec00007030

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

0510JanFebMarAprMayJunJulAugSepOctNovDeccalmAug 8 · 6 km/hMar 24 · 5 km/h
Wind speed (km/h)Feels
Jan6calm
Feb5calm
Mar5calm
Apr5calm
May5calm
Jun5calm
Jul6calm
Aug6calm
Sep6calm
Oct6calm
Nov6calm
Dec6calm

Hazard calendar for Porto Acre

In seasonPeak

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

Porto Acre's rainy season runs October–April, 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 Porto Acre

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around late July, Porto Acre 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 Porto Acre for general outdoor tourist activities is from late May to early August, with a peak score in the first week of July.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationJul 4 · 5.2

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
Jan2.7poor
Feb2.7poor
Mar2.7poor
Apr3.0poor
May4.1fair
Jun5.0fair
Jul5.0fair
Aug3.9fair
Sep3.1poor
Oct2.8poor
Nov2.7poor
Dec2.7poor

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

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 18 · 7.7

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 Porto Acre, 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.

Porto Acre packs about the same all year — highs hold near 33°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 September, Porto Acre sees daytime highs around 33°C and nights near 22°C. Pack light clothes. Worth having: rain gear and sun protection. About 13 days see rain.

UV index (midday) in Porto Acre 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 Porto Acre peaks around January 20 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near September 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 highHighExtremeJan 20UV 15Sep 10UV 5
UV index (midday)Level
Jan15Extreme
Feb15Extreme
Mar15Extreme
Apr13Extreme
May11Extreme
Jun9Very high
Jul8Very high
Aug6High
Sep5Moderate
Oct12Extreme
Nov13Extreme
Dec13Extreme

Average hourly UV index in Porto Acre

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 8.5 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)
Jan8.57
Feb8.57
Mar86.5
Apr86
May7.55
Jun74.5
Jul6.54
Aug5.50
Sep50
Oct86
Nov8.56.5
Dec8.56.5

Air quality in Porto Acre 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 Porto Acre is worst in September — around 100 µg/m³ PM2.5 (unhealthy), about 12.4× the cleanest month (June, 8 µg/m³).

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

0306090120JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateUnhealthyModerateGoodSep 1394 µg/m³Jun 98 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb13Moderate
Mar13Moderate
Apr10Good
May8Good
Jun8Good
Jul14Moderate
Aug65Unhealthy
Sep100Unhealthy
Oct27Moderate
Nov13Moderate
Dec11Good
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Porto Acre 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. Porto Acre banks about 6,040 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)
Jan514
Feb463
Mar514
Apr492
May488
Jun462
Jul483
Aug522
Sep528
Oct543
Nov510
Dec520

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.

Porto Acre receives about 4.8 kWh/m² a day of solar energy — bright — and it stays remarkably steady, holding between 4.2 and 5.6 kWh/m² all year. For solar panels, output here is a flat line, not a seasonal wave.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmoderatebrightintenseSep 255.6 kWhMay 284.2 kWh
Solar energy (kWh/m²)Level
Jan4.7Bright
Feb4.5Bright
Mar4.5Bright
Apr4.4Bright
May4.2Bright
Jun4.3Bright
Jul4.8Bright
Aug5.3Bright
Sep5.5Bright
Oct5.5Bright
Nov5.1Bright
Dec4.8Bright

Where is Porto Acre?

Porto Acre sits at 9.6°S, 67.5°W, 121 m above sea level, in Brazil. The nearest listed city is Rio Branco, 53 km away.

Topography around Porto Acre

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

Within 3 km, the terrain around Porto Acre has only modest variations in elevation — a maximum elevation change of 70 m around an average of 140 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 105 m; within 80 km, only modest variations in elevation — a maximum elevation change of 145 m.

The land around Porto Acre is covered by trees (74%) and grassland (23%) within 3 km, trees (68%) and grassland (31%) within 16 km, and trees (65%) and grassland (35%) within 80 km.

3 km
70 m
16 km
105 m
80 km
145 m
treesgrasslandartificial surfaceswater
Nearby: Rio Branco 53 km · Senador Guiomard 66 km · Plácido de Castro 91 km · Boca do Acre 94 km · Sena Madureira 138 km · Xapuri 159 km · Brasiléia 207 km · Epitaciolândia 208 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 Porto Acre (-9.5883°, -67.5325°, elevation 121 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).