Climate and average weather in Custoias

In Custoias, the summers are hot, dry, and clear and the winters are cool and partly cloudy.

Best: mid May to mid October

Over the course of the year, the temperature in Custoias typically varies from 3°C to 29°C, and is rarely below -2°C or above 34°C. July is the hottest month of the year, while January is the coldest.

Based on the travel score, the best time of year to visit Custoias for warm-weather activities is from mid May to mid October.

Hottest
Jul
29°
Coldest
Jan
Wettest
Oct
83 mm
Driest
Jul
12 mm
Rain / yr
555 mm
84 wet days
Daylight
9.0–15.0 h
shortest–longest
Elevation
569 m
41.1°N
Clearest
Jul
25% cloud

Custoias is human settlement in Portugal.

Air quality
Good
PM10 27.6 µg/m³ · 2010

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

Custoias 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 May to mid October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

The hot season lasts 3.3 months, from June 9 to September 16, with daily high temperatures above 25°C. The hottest month of the year in Custoias is July, with an average high of 29°C and low of 15°C.

The cool season lasts 3.6 months, from November 14 to March 2, with daily high temperatures below 14°C. The coldest month of the year in Custoias is January, with an average low of 3°C and high of 10°C.

Days typically run about 10°C warmer than nights, with the widest day–night swing (around 14°C) in July.

10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan103
Feb123
Mar155
Apr177
May2110
Jun2613
Jul2915
Aug2915
Sep2513
Oct1910
Nov136
Dec104

Average hourly temperature in Custoias

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

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

Custoias 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
Jan10° / 628.79.42.3
Feb12° / 436.610.43.5
Mar15° / 497.911.74.9
Apr17° / 549.813.15.6
May21° / 10°499.214.36.7
Jun26° / 13°204.814.97.8
Jul29° / 15°122.614.77.1
Aug29° / 15°133.413.67.1
Sep25° / 13°344.612.37.9
Oct19° / 10°839.310.96.3
Nov13° / 699.29.73.9
Dec10° / 688.39.12.5

Chance of rain

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

Custoias gets about 555 mm of precipitation a year. On a typical day the chance of rain is some rain, but that rises and falls sharply with the seasons.

The wetter season lasts 4.4 months, from around Oct 5 to Feb 14, peaking in October at about 34% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jul 23.

October is the wettest month by volume, with 83 mm over about 9 wet days; July is the driest, with 12 mm.

0%10%20%30%40%50%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetOct 21 · 34%Jul 23 · 8%
Rain on a day (%)Rain days
Jan289
Feb247
Mar268
Apr3210
May299
Jun165
Jul93
Aug103
Sep165
Oct309
Nov309
Dec278

Monthly rainfall

Over a full year, Custoias collects about 555 mm of rain across 84 wet days — roughly 46 mm in an average month.

It doesn’t fall evenly. October is the wettest month with 83 mm, while July is the driest at just 12 mm. The three wettest months alone bring about 40% of the year’s total.

0255075100JanFebMarAprMayJunJulAugSepOctNovDec624349544920121334836968
Rainfall (mm)Rain days
Jan629
Feb437
Mar498
Apr5410
May499
Jun205
Jul123
Aug133
Sep345
Oct839
Nov699
Dec688

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Custoias, 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 24 and lasts for 4.5 months, ending around October 6. The clearest month is July, when the sky is clear, mostly clear, or partly cloudy 85% of the time on average.

The cloudier part of the year begins around October 7 and lasts for 7.5 months, ending around May 23. The cloudiest month is December, when it is overcast or mostly cloudy 62% 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 26 · 88%Jan 1 · 37%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan4159
Feb4753
Mar4654
Apr4654
May5050
Jun6832
Jul8515
Aug8416
Sep7030
Oct4753
Nov4060
Dec3862

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 June 18, brings about 15 hours of light; the shortest, around December 17, only 9 hours — a swing of roughly 6 hours.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.47:585:19
Feb10.47:335:55
Mar11.76:496:29
Apr13.15:577:02
May14.35:177:34
Jun14.95:017:58
Jul14.75:147:56
Aug13.65:447:23
Sep12.36:166:32
Oct10.96:485:41
Nov9.77:255:04
Dec9.17:544:57

Sunny days

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

Custoias averages about 12 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 7 and 24 days.

The sunnier stretch runs 4.1 months, from around Jun 3 to Oct 6. The sunniest month is July, with roughly 22 sunny days (bright).

The greyest month is December, down near 7 sunny days — about 68% fewer than the July peak.

051015202530JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightbrilliantJul 2624 daysDec 87 days
Sunny daysSky
Jan8Mixed
Feb10Mixed
Mar10Mixed
Apr9Mixed
May10Mixed
Jun15Bright
Jul23Bright
Aug21Bright
Sep16Bright
Oct10Mixed
Nov8Mixed
Dec7Gloomy

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 Custoias, the air stays dry or comfortable essentially all year. Even in August, the muggiest month, it feels humid or worse only about 4% of the time — humidity is not something you need to plan around here.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDeccomfortabledry
Dry (%)Comfortable (%)Humid (%)
Jan10000
Feb10000
Mar10000
Apr10000
May9550
Jun76222
Jul58384
Aug57384
Sep74251
Oct86131
Nov9730
Dec10000

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 Custoias is steady company: average speeds sit near 9 km/hcalm — in every month of the year, with no meaningful windy or calm season.

051015JanFebMarAprMayJunJulAugSepOctNovDeccalmlight breezeApr 1 · 10 km/hAug 29 · 8 km/h
Wind speed (km/h)Feels
Jan8calm
Feb9calm
Mar9calm
Apr9calm
May9calm
Jun9calm
Jul8calm
Aug8calm
Sep8calm
Oct9calm
Nov9calm
Dec8calm

Best time to visit Custoias

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around late May, Custoias 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 Custoias for general outdoor tourist activities is from mid May to mid October, with a peak score in the second week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationSep 9 · 8.0

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
Jan2.3poor
Feb3.5poor
Mar4.9fair
Apr5.6good
May6.7good
Jun7.8ideal
Jul7.1good
Aug7.1good
Sep7.9ideal
Oct6.2good
Nov3.9fair
Dec2.5poor

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 Custoias for hot-weather activities is from mid June to mid September, with a peak score in the last week of July.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 22 · 8.9

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 Custoias, 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 July (highs near 29°C), the essentials are light clothes and sun protection. In the cold season around January (highs near 10°C), pack a warm layer and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Custoias sees daytime highs around 29°C and nights near 15°C. Pack light clothes and sun protection.

UV index (midday) in Custoias 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 Custoias peaks around July 12 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 12UV 9Dec 20UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5High
Apr6High
May7High
Jun9Very high
Jul9Very high
Aug9Very high
Sep6High
Oct5Moderate
Nov2Moderate
Dec2Low

Average hourly UV index in Custoias

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 July the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 5.5 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)
Jan00
Feb00
Mar50
Apr6.52
May7.53
Jun8.55.5
Jul8.55.5
Aug85
Sep61
Oct4.50
Nov00
Dec00

Air quality in Custoias 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 Custoias is worst in August — around 22 µg/m³ PM2.5 (moderate), about 3.2× the cleanest month (November, 7 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodModerateGoodAug 1922 µg/m³Nov 237 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb10Good
Mar13Moderate
Apr11Good
May8Good
Jun9Good
Jul12Good
Aug22Moderate
Sep18Moderate
Oct13Moderate
Nov7Good
Dec7Good
Almanac & agriculture

Growing season

Chance of a frost-free dayReliably frost-free (≥90%)

Custoias is mild enough that a frost-free day stays more likely than not even in midwinter. Nights are reliably above freezing from about March 4 to November 22 (264 days); outside that window a hard frost is an occasional risk.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecreliably frost-freeMar 490%Nov 2290%
Frost-free chance (%)Frost nights
Jan7831
Feb8428
Mar954
Apr990
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov946
Dec8231

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. Custoias banks about 1,685 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

05001,0001,500JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan0
Feb0
Mar14
Apr62
May168
Jun282
Jul372
Aug369
Sep264
Oct141
Nov13
Dec0

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.

Custoias receives about 4.5 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 1.6 and 7.5 kWh/m².

The brighter stretch of the year lasts 6.1 months, from around Mar 23 to Sep 23. The brightest month is July, averaging about 7.5 kWh/m² (intense).

The dimmest month is December, down near 1.6 kWh/m² — roughly 79% less than the July peak.

0123456789JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJul 147.5 kWhDec 251.6 kWh
Solar energy (kWh/m²)Level
Jan1.8Dim
Feb2.9Moderate
Mar4.2Bright
Apr5.3Bright
May6.3Intense
Jun7.2Intense
Jul7.5Intense
Aug6.6Intense
Sep5.0Bright
Oct3.2Moderate
Nov2.0Moderate
Dec1.6Dim

Where is Custoias?

Custoias sits at 41.1°N, 7.3°W, 569 m above sea level, in Portugal. The nearest listed city is Vila Nova de Foz Côa, 15 km away.

Topography around Custoias

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

Within 3 km, the terrain around Custoias has large variations in elevation — a maximum elevation change of 671 m around an average of 479 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 921 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,573 m.

The land around Custoias is covered by shrubs (40%), grassland (30%) and trees (29%) within 3 km, grassland (44%), trees (26%) and shrubs (23%) within 16 km, and grassland (58%) and trees (30%) within 80 km.

3 km
671 m
16 km
921 m
80 km
1,573 m
treesshrubsgrasslandcroplandartificial surfaceswater
Nearby: Vila Nova de Foz Côa 15 km · Vila Real 41 km · Baião 60 km · Sequeira 62 km · Guarda 63 km · Viseu 70 km · Chaves 72 km · Cabeceiras de Basto 72 km

Portugal travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / E / F
230 V · 50 Hz
Prices
≈ 60% of US
price level, 2025
GDP per capita
$32,082
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
95%
of population, 2024
Homicide rate
0.7
per 100k, 2022
Road deaths
8.2
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 612
Religion
Catholic 68%not applicable 13%no religion 12%no response 2%

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 Custoias (41.1053°, -7.321°, elevation 569 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).