Climate and average weather in Barreirinhas

In Barreirinhas, the weather is muggy, hot, wet, and mostly clear and remarkably steady, with daytime highs holding near hot levels all year. The wettest stretch peaks around April.

Best: early June to late December

Over the course of the year, the temperature in Barreirinhas typically varies from 24°C to 32°C, and is rarely below 23°C or above 34°C. August is the hottest month of the year, while March is the coldest.

Based on the travel score, the best time of year to visit Barreirinhas for warm-weather activities is from early June to late December.

Hottest
Aug
32°
Coldest
Mar
24°
Wettest
Apr
303 mm
Driest
Sep
3 mm
Rain / yr
1286 mm
158 wet days
Daylight
11.8–12.2 h
shortest–longest
Elevation
5 m
2.8°S
Clearest
Sep
28% cloud

Barreirinhas is principal settlement in Barreirinhas Municipality, Maranhão, Brazil.

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

Barreirinhas 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 June to late December.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

Temperatures in Barreirinhas stay fairly even through the year, without a distinct hot or cool season. The warmest month is August, with an average high of 32°C and low of 25°C; the coolest is March, with an average low of 24°C and high of 30°C.

Days typically run about 6°C warmer than nights year-round.

20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan3125
Feb3024
Mar3024
Apr3024
May3025
Jun3125
Jul3125
Aug3225
Sep3225
Oct3225
Nov3226
Dec3225

How hot and cold Barreirinhas 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, Barreirinhas feels like about 37°C (around May 14). Nearly every day a year carries some heat stress, peaking in May.

20°25°30°35°40°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan35312525
Feb35302424
Mar35302424
Apr36302424
May37302525
Jun35312525
Jul35312525
Aug36322525
Sep36322525
Oct36322525
Nov36322526
Dec36322525

Average hourly temperature in Barreirinhas

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 32°C, and coldest before dawn in March, near 24°C.

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

Barreirinhas 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
Jan31° / 25°14021.612.13.4
Feb30° / 24°20424.212.13.1
Mar30° / 24°27829122.8
Apr30° / 24°30327.211.92.9
May30° / 25°19222.111.93.5
Jun31° / 25°6613.111.84.6
Jul31° / 25°386.811.95.1
Aug32° / 25°71.511.95.1
Sep32° / 25°30.8125.1
Oct32° / 25°60.812.15.1
Nov32° / 26°112.412.14.9
Dec32° / 25°378.412.24.4

Chance of rain

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

Barreirinhas gets about 1286 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 5.6 months, from around Dec 27 to Jun 15, peaking in March at about 96% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Sep 10.

April is the wettest month by volume, with 303 mm over about 27 wet days; September is the driest, with 3 mm.

0%10%20%30%40%50%60%70%80%90%100%110%JanFebMarAprMayJunJulAugSepOctNovDecwetterdriermostly drysome rainoften wetvery wetMar 26 · 96%Sep 10 · 2%
Rain on a day (%)Rain days
Jan6922
Feb8524
Mar9329
Apr9027
May7122
Jun4413
Jul227
Aug52
Sep31
Oct31
Nov82
Dec288

Monthly rainfall

Over a full year, Barreirinhas collects about 1286 mm of rain across 158 wet days — roughly 107 mm in an average month.

It doesn’t fall evenly. April is the wettest month with 303 mm, while September is the driest at just 3 mm. The three wettest months alone bring about 61% of the year’s total.

050100150200250300350JanFebMarAprMayJunJulAugSepOctNovDec14020427830319266387361137
Rainfall (mm)Rain days
Jan14022
Feb20424
Mar27829
Apr30327
May19222
Jun6613
Jul387
Aug72
Sep31
Oct61
Nov112
Dec378

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Barreirinhas, 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 30 and lasts for 6.5 months, ending around December 14. The clearest month is September, when the sky is clear, mostly clear, or partly cloudy 94% of the time on average.

The cloudier part of the year begins around December 15 and lasts for 5.5 months, ending around May 29. The cloudiest month is March, when it is overcast or mostly cloudy 84% 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%JanFebMarAprMayJunJulAugSepOctNovDecSep 5 · 96%Mar 27 · 12%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearer
Clearer (%)Cloudier (%)
Jan3169
Feb2278
Mar1684
Apr1783
May4258
Jun7426
Jul8614
Aug937
Sep946
Oct8515
Nov6931
Dec5545

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. Close to the equator, Barreirinhas barely changes through the year: days stay near 12 h 12 min of light in every season.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan12.15:566:05
Feb12.16:036:09
Mar12.06:006:02
Apr11.95:535:50
May11.95:515:44
Jun11.85:565:47
Jul11.96:015:53
Aug11.95:585:53
Sep12.05:465:45
Oct12.15:345:38
Nov12.15:335:40
Dec12.25:435:52

Sunny days

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

Barreirinhas averages about 12 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 1 and 26 days.

The sunnier stretch runs 6.0 months, from around Jun 6 to Dec 6. The sunniest month is September, with roughly 25 sunny days (brilliant).

The greyest month is March, down near 2 sunny days — about 93% fewer than the September peak.

051015202530JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightbrilliantSep 526 daysMar 291 days
Sunny daysSky
Jan4Gloomy
Feb3Gloomy
Mar2Gloomy
Apr2Gloomy
May7Gloomy
Jun15Bright
Jul20Bright
Aug24Brilliant
Sep25Brilliant
Oct21Bright
Nov14Mixed
Dec11Mixed

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.

Barreirinhas 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 January, the mildest month, the air is dry or comfortable only 0% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecmiserableoppressive
Muggy (%)Oppressive (%)Miserable (%)
Jan07921
Feb05941
Mar04555
Apr03268
May03070
Jun07030
Jul3943
Aug7930
Sep5950
Oct2980
Nov1991
Dec0946

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.

Across the year, average wind speed in Barreirinhas is typically light breeze, near 14 km/h, and varies moderately with the seasons.

The windier part of the year lasts 5.2 months, from around Aug 2 to Jan 6. The windiest month is October, averaging about 20 km/h (light breeze).

The calmer part of the year runs from around Jan 7 to Aug 1, with April the calmest month at about 10 km/h.

0510152025JanFebMarAprMayJunJulAugSepOctNovDeccalmerwindiercalmlight breezebreezyOct 14 · 20 km/hApr 26 · 10 km/h
Wind speed (km/h)Feels
Jan14light breeze
Feb12light breeze
Mar11calm
Apr10calm
May11calm
Jun12calm
Jul13light breeze
Aug16light breeze
Sep19light breeze
Oct20light breeze
Nov19light breeze
Dec17light breeze

Hazard calendar for Barreirinhas

In seasonPeak

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

Barreirinhas's monsoon runs January–May, 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 Barreirinhas

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around mid June, Barreirinhas is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

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 Barreirinhas for general outdoor tourist activities is from early June to late December, with a peak score in the last week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationSep 26 · 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
Jan3.4poor
Feb3.1poor
Mar2.9poor
Apr2.9poor
May3.5fair
Jun4.5fair
Jul5.1fair
Aug5.0fair
Sep5.1fair
Oct5.1fair
Nov4.9fair
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 Barreirinhas for hot-weather activities is from late June to mid December, with a peak score in the second week of September.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationSep 14 · 8.3

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 Barreirinhas, 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.

Barreirinhas packs about the same all year — highs hold near 32°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, Barreirinhas sees daytime highs around 32°C and nights near 25°C. Pack light clothes and sun protection.

Sea temperature near Barreirinhas

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 27 km away) is warmest in April at about 29°C and coldest in September near 27°C.

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

26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan28Tropical
Feb28Tropical
Mar29Tropical
Apr29Tropical
May29Tropical
Jun29Tropical
Jul28Warm
Aug27Warm
Sep27Warm
Oct27Warm
Nov28Warm
Dec28Warm

UV index (midday) in Barreirinhas 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 Barreirinhas peaks around March 16 at about 16 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 15 at about 10 (extreme).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeMar 16UV 16Jul 15UV 10
UV index (midday)Level
Jan13Extreme
Feb14Extreme
Mar16Extreme
Apr14Extreme
May12Extreme
Jun10Extreme
Jul10Extreme
Aug11Extreme
Sep12Extreme
Oct12Extreme
Nov11Extreme
Dec12Extreme

Average hourly UV index in Barreirinhas

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 March 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)
Jan86.5
Feb86.5
Mar8.57
Apr86.5
May86
Jun7.55
Jul7.55
Aug7.55.5
Sep86
Oct86
Nov7.55.5
Dec86

Air quality in Barreirinhas 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 Barreirinhas is worst in July — around 20 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (May, 8 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateGoodModerateJul 1719 µg/m³May 219 µg/m³
PM2.5 (µg/m³)Level
Jan12Moderate
Feb15Moderate
Mar14Moderate
Apr11Good
May8Good
Jun9Good
Jul20Moderate
Aug12Good
Sep9Good
Oct11Good
Nov14Moderate
Dec14Moderate
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Barreirinhas 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. Barreirinhas banks about 6,514 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around November.

02,0004,0006,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan546
Feb480
Mar526
Apr511
May541
Jun526
Jul550
Aug571
Sep556
Oct576
Nov559
Dec572

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.

Barreirinhas receives about 5.8 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.9 and 6.8 kWh/m².

The brighter stretch of the year lasts 5.3 months, from around Jul 24 to Dec 30. The brightest month is October, averaging about 6.8 kWh/m² (intense).

The dimmest month is April, down near 4.9 kWh/m² — roughly 28% less than the October peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmoderatebrightintenseOct 76.8 kWhApr 254.9 kWh
Solar energy (kWh/m²)Level
Jan5.5Bright
Feb5.3Bright
Mar5.1Bright
Apr4.9Bright
May5.1Bright
Jun5.3Bright
Jul5.6Bright
Aug6.3Intense
Sep6.7Intense
Oct6.8Intense
Nov6.5Intense
Dec6.1Intense

Where is Barreirinhas?

Barreirinhas sits at 2.8°S, 42.8°W, 5 m above sea level, in Brazil. The nearest listed city is Paulino Neves, 33 km away.

Topography around Barreirinhas

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

Within 3 km, the terrain around Barreirinhas has only modest variations in elevation — a maximum elevation change of 25 m around an average of 8 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 76 m; within 80 km, only modest variations in elevation — a maximum elevation change of 138 m.

The land around Barreirinhas is covered by grassland (36%) and trees (29%) within 3 km, trees (46%) and grassland (20%) within 16 km, and trees (39%) and water (30%) within 80 km.

3 km
25 m
16 km
76 m
80 km
138 m
treesshrubsgrasslandartificial surfacesbare terrainwaterwetlandmangroves
Nearby: Paulino Neves 33 km · Tutóia 61 km · Humberto de Campos 73 km · São Bernardo 81 km · Urbano Santos 82 km · Santa Quitéria do Maranhão 87 km · Luzilândia 93 km · São Benedito do Rio Preto 101 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 Barreirinhas (-2.7556°, -42.8259°, elevation 5 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).