Climate and average weather in Ílhavo

In Ílhavo, the summers are warm, fairly dry, and clear and the winters are cool and partly cloudy.

Best: late May to late September

Over the course of the year, the temperature in Ílhavo typically varies from 8°C to 24°C, and is rarely below 5°C or above 30°C. August is the hottest month of the year, while January is the coldest.

Based on the travel score, the best time of year to visit Ílhavo for warm-weather activities is from late May to late September.

Hottest
Aug
24°
Coldest
Jan
Wettest
Nov
133 mm
Driest
Jul
10 mm
Rain / yr
943 mm
101 wet days
Daylight
9.1–14.9 h
shortest–longest
Elevation
13 m
40.6°N
Clearest
Jul
26% cloud

Ílhavo is city seat of Ílhavo municipality.

Air quality
Good
PM10 23.2 µg/m³ · 2019

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

Ílhavo 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 late September.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

The hot season lasts 3.6 months, from June 10 to September 27, with daily high temperatures above 22°C. The hottest month of the year in Ílhavo is August, with an average high of 24°C and low of 17°C.

The cool season lasts 3.5 months, from November 21 to March 5, with daily high temperatures below 16°C. The coldest month of the year in Ílhavo is January, with an average low of 8°C and high of 14°C.

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

10°15°20°25°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan148
Feb159
Mar1710
Apr1811
May2013
Jun2216
Jul2417
Aug2417
Sep2316
Oct2014
Nov1611
Dec149

Average hourly temperature in Ílhavo

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 24°C, and coldest before dawn in January, near C.

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

Ílhavo 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
Jan14° / 11911.69.43.9
Feb15° / 83910.44.4
Mar17° / 10°889.711.75.4
Apr18° / 11°9210.7135.7
May20° / 13°72914.26.6
Jun22° / 16°244.714.87.9
Jul24° / 17°102.214.68.9
Aug24° / 17°153.113.68.7
Sep23° / 16°485.612.37.9
Oct20° / 14°13211.410.96.2
Nov16° / 11°13312.59.75.0
Dec14° / 12911.29.14.2

Chance of rain

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

Ílhavo gets about 943 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 7.6 months, from around Oct 3 to May 21, peaking in October at about 42% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jul 21.

November is the wettest month by volume, with 133 mm over about 13 wet days; July is the driest, with 10 mm.

0%10%20%30%40%50%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetOct 24 · 42%Jul 21 · 6%
Rain on a day (%)Rain days
Jan3812
Feb329
Mar3110
Apr3511
May299
Jun165
Jul82
Aug93
Sep196
Oct3711
Nov4013
Dec3711

Monthly rainfall

Over a full year, Ílhavo collects about 943 mm of rain across 101 wet days — roughly 79 mm in an average month.

It doesn’t fall evenly. November is the wettest month with 133 mm, while July is the driest at just 10 mm. The three wettest months alone bring about 42% of the year’s total.

0255075100125150175JanFebMarAprMayJunJulAugSepOctNovDec1198388927224101548132133129
Rainfall (mm)Rain days
Jan11912
Feb839
Mar8810
Apr9211
May729
Jun245
Jul102
Aug153
Sep486
Oct13211
Nov13313
Dec12911

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Ílhavo, 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 26 and lasts for 4.3 months, ending around October 4. 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 5 and lasts for 7.7 months, ending around May 25. The cloudiest month is December, when it is overcast or mostly cloudy 52% 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 28 · 89%Nov 1 · 45%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan5248
Feb5248
Mar5644
Apr5644
May6040
Jun7228
Jul8614
Aug8515
Sep7327
Oct5446
Nov4951
Dec4852

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 12, brings about 14 h 54 min of light; the shortest, around January 1, only 9 h 06 min — a swing of roughly 5 h 48 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.48:025:26
Feb10.47:386:01
Mar11.76:546:34
Apr13.06:037:07
May14.25:237:38
Jun14.85:088:02
Jul14.65:217:59
Aug13.65:507:28
Sep12.36:216:37
Oct10.96:535:47
Nov9.77:295:11
Dec9.17:585:04

Sunny days

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

Ílhavo averages about 14 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 9 and 24 days.

The sunnier stretch runs 4.2 months, from around Jun 1 to Oct 6. The sunniest month is July, with roughly 22 sunny days (bright).

The greyest month is November, down near 10 sunny days — about 54% fewer than the July peak.

051015202530JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedbrightbrilliantJul 2824 daysNov 19 days
Sunny daysSky
Jan12Mixed
Feb11Mixed
Mar12Mixed
Apr11Mixed
May12Mixed
Jun16Bright
Jul22Bright
Aug22Bright
Sep17Bright
Oct12Mixed
Nov10Mixed
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.

In Ílhavo, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 4.5 months, from around June 9 to October 22. The muggiest month is July, when the air feels humid, muggy or worse about 55% of the time.

The most comfortable stretch runs from around October 23 to June 8, and January is the most comfortable month — the air is dry or comfortable 100% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJan 16 · 100%Jul 26 · 36%humiddrycomfortablecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)
Jan96400
Feb98200
Mar97300
Apr891100
May623260
Jun2550241
Jul838523
Aug633565
Sep1641412
Oct3941191
Nov781840
Dec93700

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 Ílhavo is steady company: average speeds sit near 15 km/hlight breeze — in every month of the year, with no meaningful windy or calm season.

05101520JanFebMarAprMayJunJulAugSepOctNovDeccalmlight breezeDec 26 · 16 km/hSep 11 · 13 km/h
Wind speed (km/h)Feels
Jan16light breeze
Feb15light breeze
Mar15light breeze
Apr16light breeze
May15light breeze
Jun15light breeze
Jul16light breeze
Aug15light breeze
Sep13light breeze
Oct14light breeze
Nov15light breeze
Dec16light breeze

Hazard calendar for Ílhavo

In seasonPeak

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

Ílhavo's rainy season runs October–May, 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 Ílhavo

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around late September, Ílhavo 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 Ílhavo for general outdoor tourist activities is from early June to late September, with a peak score in the third week of July.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationJul 19 · 9.0

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
Jan3.9fair
Feb4.4fair
Mar5.4fair
Apr5.7good
May6.6good
Jun7.9ideal
Jul8.9ideal
Aug8.7ideal
Sep7.9ideal
Oct6.2good
Nov5.0fair
Dec4.2fair

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

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 28 · 7.8

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 Ílhavo, 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 August (highs near 24°C), the essentials are light clothes and sun protection. In the cold season around January (highs near 14°C), pack a warm layer and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In August, Ílhavo sees daytime highs around 24°C and nights near 17°C. Pack sun protection. Worth having: light clothes. About 3 days see rain.

Sea temperature near Ílhavo

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 17 km away) is warmest in August at about 18°C and coldest in February near 14°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

12°14°16°18°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°C)Comfort
Jan14Bracing
Feb14Bracing
Mar14Bracing
Apr15Bracing
May16Cool
Jun17Cool
Jul18Cool
Aug18Cool
Sep18Cool
Oct17Cool
Nov16Cool
Dec15Bracing

UV index (midday) in Ílhavo 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 Ílhavo peaks around July 11 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 11UV 9Dec 20UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May7High
Jun9Very high
Jul9Very high
Aug8Very high
Sep5High
Oct4Moderate
Nov2Moderate
Dec2Low

Average hourly UV index in Ílhavo

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 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
Apr6.51.5
May7.53.5
Jun8.55
Jul8.55
Aug7.54.5
Sep5.50
Oct40
Nov00
Dec00

Air quality in Ílhavo 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 Ílhavo is worst in October — around 19 µg/m³ PM2.5 (moderate), about 2.8× the cleanest month (November, 7 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodOct 1119 µg/m³Nov 237 µg/m³
PM2.5 (µg/m³)Level
Jan7Good
Feb9Good
Mar11Good
Apr10Good
May8Good
Jun12Good
Jul8Good
Aug14Moderate
Sep17Moderate
Oct19Moderate
Nov7Good
Dec7Good
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Ílhavo 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. Ílhavo banks about 2,102 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around August.

05001,0001,5002,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan29
Feb42
Mar102
Apr133
May202
Jun269
Jul323
Aug332
Sep284
Oct221
Nov113
Dec54

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.

Ílhavo receives about 4.6 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 1.8 and 7.4 kWh/m².

The brighter stretch of the year lasts 6.2 months, from around Mar 20 to Sep 23. The brightest month is July, averaging about 7.3 kWh/m² (intense).

The dimmest month is December, down near 1.8 kWh/m² — roughly 75% less than the July peak.

012345678JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJul 97.4 kWhDec 231.8 kWh
Solar energy (kWh/m²)Level
Jan2.1Moderate
Feb3.1Moderate
Mar4.4Bright
Apr5.5Bright
May6.5Intense
Jun7.2Intense
Jul7.3Intense
Aug6.5Intense
Sep5.0Bright
Oct3.4Moderate
Nov2.2Moderate
Dec1.8Dim

Where is Ílhavo?

Ílhavo sits at 40.6°N, 8.7°W, 13 m above sea level, in Portugal. The nearest listed city is Vilar, 4.0 km away.

Topography around Ílhavo

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

Within 3 km, the terrain around Ílhavo has only modest variations in elevation — a maximum elevation change of 55 m around an average of 14 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 126 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,365 m.

The land around Ílhavo is covered by grassland (23%), trees (21%) and artificial surfaces (20%) within 3 km, water (31%) and trees (30%) within 16 km, and trees (46%) and water (27%) within 80 km.

3 km
55 m
16 km
126 m
80 km
1,365 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
Nearby: Vilar 4.0 km · Aveiro 5.0 km · Ovar 29 km · São João da Madeira 37 km · Feira 38 km · Eiras 45 km · Espinho 45 km · São Paulo de Frades 46 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 Ílhavo (40.6019°, -8.6702°, elevation 13 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).