🇵🇹 Porto Climate Health Index

Friday, 7 August 2026 · updated 10:33 UTC · refreshes live through the day · LIVE

Modelled estimates · Medically reviewed guidance · Not an official warning service

^est. = index derived by Mobi Doctor's model from the weather inputs. All values are modelled estimates from European weather and atmospheric forecast systems (Open-Meteo · CAMS/Copernicus) — not direct readings from a monitoring station in this city, and not official public-health warnings.

The Climate Health Score for Porto today is 6.1/10 — high exposure on a 0–10 scale where 10 is extreme. It reflects the worst of ten live hazard readings for Porto — heat, UV, air quality, pollen, hydration demand, allergy, mosquito activity, fire weather, flu season and cold — and is recalculated through the day by Mobi Doctor's European Climate Health Index.

How heat behaves in Porto

Porto's northern Atlantic position keeps most summers gentle, which is precisely its vulnerability: rare sharp heatwaves arrive on a population and housing stock with little acclimatisation or cooling. Risk here concentrates almost entirely in a handful of spike days.

Porto is a granite city built against Atlantic damp: thick-walled, north-facing, made to hold warmth in. That inheritance turns rare heatwaves inside out — the housing stores exactly what the weather delivers, and its dense, ageing riverside parishes have some of Portugal's oldest populations in buildings without cooling. The Douro gorge adds its own twist: the river-level quays regularly run hotter and stiller than the breezier ridge of the upper town.

Heat and your health in Porto today

Feels-like maximum 27°C (air temperature 24°C) · tonight's minimum 18°C · humidity 75% · heat pillar score 1.3/10

Where today sits in Porto's year: the heat season here typically runs July to August, moderate — risk concentrates in rare spike episodes, peaking late July to mid-August. Tropical nights in Porto: rare — an exceptional-heatwave phenomenon rather than a seasonal pattern.

Heat stresses the body long before heatstroke. As the air temperature and humidity climb, your heart works harder to push blood to the skin for cooling, you lose fluid and electrolytes through sweat, and blood pressure can dip when you stand. That is why hot days bring more dizziness, fainting, migraines, kidney strain and falls — and studies of heatwave hospital admissions also report more urinary tract infections, thought to be linked to dehydration — not just classic heat exhaustion.

Night temperature matters as much as the daytime peak. When a night stays above 20°C — a tropical night — the cardiovascular system gets far less of its overnight recovery window — one reason heatwave mortality tracks hot nights more closely than hot afternoons. Tonight in Porto drops to around 18°C, which gives the body a proper recovery window.

Pollen count in Porto today

Pollen levels are currently minimal · score 0.2/10

Porto's pollen calendar: Grass April–June · olive May–June · plane and birch traces in spring. The live counts above show where today falls in that cycle.

Pollen allergy (hay fever) is triggered by different plants through the year: trees like birch and alder in spring, grasses in early summer, and weeds such as mugwort and ragweed from late July into autumn. Symptoms — sneezing, itchy eyes, a blocked nose, worsened asthma — flare when daily counts cross species-specific thresholds, and air pollution makes the same pollen load feel worse by priming the airways.

On high-count days: keep windows closed in the early morning and evening, shower and change after time outdoors, and start antihistamines before symptoms peak rather than after. If you use an asthma inhaler, keep it with you on high pollen days.

Allergy load in Porto today: pollen × air quality

Combined pollen-and-air allergy load 0.6/10 — pollen 0.2 amplified by air quality (EAQI 24) · estimated from live data

Porto's plane trees line dense granite streets where traffic idles, pairing spring pollen with the exhaust that primes airways; grass follows on the Atlantic wind. Humid air keeps loads moderate but persistent through the season.

Allergy risk is more than the pollen count. Exhaust particles damage the airway lining and prime the immune response, so the same grains provoke stronger symptoms on polluted days — and pollutant-stressed plants release more allergenic protein per grain. This combined score therefore reads pollen and air quality together: identical counts can feel very different on clean and dirty days, which is why it is tracked as its own pillar rather than folded into either input.

Today the combination is modest — sensitised people can treat this as a normal day, with the usual seasonal routine.

UV index in Porto today

Maximum UV index 7.6 · high on the WHO scale

Porto's strong-UV season: May to September — midday index 8–9 under clear skies.

UV radiation peaks between late morning and mid-afternoon and is invisible — it burns on cool, cloudy days too. At UV 8 and above, unprotected fair skin can burn in under 30 minutes. Repeated burns drive most skin-cancer risk, and some common medicines (certain antibiotics, diuretics, acne treatments) make skin dramatically more sun-sensitive.

Today: SPF 30–50 on exposed skin, sunglasses, and shade between 11:00 and 16:00. Reapply sunscreen every two hours outdoors.

Air quality in Porto today

European AQI 24 · fair (EAQI scale: 0 good → 100+ worst) · PM2.5 8.5 µg/m³ · ozone 60 µg/m³ · score 1.9/10

Porto's air is Atlantic-cleaned most of the year; winter evenings add wood-smoke particles across the metro area, and rare summer heat episodes bring the region's only meaningful ozone days.

Fine particles (PM2.5) reach deep into the lungs and bloodstream; ozone forms in sunny, hot weather and irritates the airways — which is why heatwaves and smog often arrive together. People with asthma, COPD, heart disease, pregnant women and children feel the effects first: more wheeze, more inhaler use, more chest tightness.

Levels are acceptable for outdoor activity today for most people, including sensitive groups.

Fire weather around Porto today

Fire-weather score 0.5/10 — 24°C, 75% humidity, wind to 12 km/h · estimated (weather conduciveness, not active fires)

The hills of northern and central Portugal burn severely in bad years — October 2017 dropped ash on the city itself — and the Douro's terraced backcountry dries fast in heat. The score signals that regional readiness; city smoke days follow the interior's fires.

This pillar scores how conducive the weather is to wildfire — heat, dry air and wind, the published Angström approach — not actual fires. Its health meaning is smoke: wildfire smoke is concentrated fine particulate that can travel hundreds of kilometres, and a smoke episode hits the same people hardest as any pollution spike — asthma, COPD, heart disease, pregnancy, young children and older adults.

Conditions are not notably fire-conducive today. If you see or smell smoke regardless, treat it like a pollution episode: head indoors, close the windows, and postpone outdoor exertion.

Hydration in Porto today

Hydration demand score 1.0/10 · estimated from live weather

Porto's cool damp norm builds no drinking habit — which is the trap when a spike arrives: on the few genuinely hot days, residents and visitors alike run hours behind their losses simply because nothing here ever taught them to pre-drink.

Fluid needs are not fixed — they scale with heat, humidity, dry air, UV and activity. Thirst lags behind need, especially in older adults, whose thirst signal weakens with age. Dark urine, headache, and light-headedness on standing are earlier and more reliable signals.

Today's guidance: Normal — drink to thirst; keep water with you on long outings.

Mosquito activity in Porto tonight

Mosquito activity score 5.1/10 — tonight around 18°C at 75% humidity · estimated from live weather (activity, not disease risk)

Mosquito season in Porto: June to September, light dusk nuisance. The score above places tonight inside that season using live temperature and humidity.

Mosquitoes fly when nights are warm and humid enough — activity climbs steeply once evenings hold above about 15°C and peaks on still, muggy nights. Southern Europe adds the tiger mosquito, a day-biter now established across much of the Mediterranean, whose continued spread north ECDC tracks. In parts of southern and central Europe, late summer also brings limited local transmission of mosquito-borne infections such as West Nile virus — an activity score is not a disease-risk score, but high-activity weeks are when precautions earn their keep.

Practical: use a repellent containing DEET or icaridin at dusk, cover ankles and wrists outdoors in the evening, screen or close windows at night, and empty standing water on balconies weekly. Speak to a doctor about any fever that develops in the week after heavy bite exposure in an affected region.

Flu season in Porto: where today sits

Flu-season level 0.5/10 · seasonal climatology (ECDC winter pattern), not live case counts

Flu reaches Porto with the December rains and peaks in January, working through a compact city that spends winter indoors. Summer sits at the floor. The campaign from October is the local rhythm, and damp winter housing makes the respiratory season heavier here.

Influenza in Europe is sharply seasonal: transmission runs low through summer, builds from late autumn as life moves indoors and cool, dry air favours the virus, then peaks between December and February in ECDC's surveillance pattern. This pillar follows that climatology — it tells you where the calendar sits, not this week's case counts, and we label it that way rather than dress a seasonal curve up as live surveillance.

What to do with it: the score rising through autumn is the cue that vaccination time has arrived — October to November gives antibodies time to build before the peak, and matters most for over-65s, pregnant women, young children and anyone with heart, lung, kidney or immune conditions. At today's low seasonal level, a summer fever is far more likely to be something other than flu — and worth a doctor's opinion if it lasts.

Cold stress in Porto: the other end of the index

Cold-stress score 0.0/10 — tonight's minimum around 18°C

Porto's winter is Atlantic — 5–8°C, wet, rarely freezing — but granite housing with minimal heating holds a penetrating damp chill, the same indoor-cold pattern that drives Portugal's high winter excess mortality. Outdoor frost is uncommon; indoor cold is the local hazard.

Across Europe, cold claims more lives each year than heat — mostly quietly, through winter's extra heart attacks, strokes and respiratory infections rather than hypothermia. Cold air raises blood pressure and thickens blood within minutes, narrows airways, and stresses hearts hardest in the first snaps of the season, before bodies and habits adjust. Indoor cold in poorly heated homes does as much damage as the weather outside.

Cold is not a factor today — the score sits low, and this pillar will matter again when the season turns. It stays on the page year-round because an honest index needs both ends of the thermometer.

The Porto climate-health year

The Porto year is mostly gentle — grey, mild, damp-edged — with a grass and olive pollen season from April to June and a summer that usually peaks in the high 20s. Its medical significance concentrates in the exceptional: every few summers an Iberian heat dome pushes past the maritime defence and delivers 38–40°C to a city with near-zero acclimatisation, minimal air conditioning and no cultural heat routine. Those short episodes carry most of the city's annual heat risk.

Typical seasonal patterns from established climatology — the live scores above always reflect today's actual conditions.

Visiting Porto? What travellers should know

Porto's compact centre invites accidental exertion: the descent to the Ribeira is easy, the climb back is 60 metres of stairs in whatever heat the day holds, and the Dom Luís I upper deck is fully exposed steel. On hot days copy the local pattern — mornings on foot, afternoons in cellars and museums (the port lodges hold cellar temperatures year-round), evenings back outside. Remember the Douro valley day trip runs five to ten degrees hotter than the coast; Pinhão in July is a different climate from Porto.

If you do get ill away from home, you don't have to navigate a foreign health system for something a consultation can solve: speak to a Mobi Doctor physician online from your hotel or apartment.

Medicines in Porto this week

Temperatures are currently inside normal storage ranges. Standard advice applies: keep medicines below 25°C, out of direct sun, and never in a parked vehicle.

Should I speak to a doctor about heat symptoms?

Heat illness escalates in stages, and the right response depends on which stage you're seeing. Use these three tiers:

Local numbers in Portugal: 112 — EU-wide emergencies · SNS 24 — 808 24 24 24 · for non-urgent concerns, a Mobi Doctor physician is online in minutes.

General guidance, not a personal assessment — when in doubt, call. In an emergency always call 112.

Sources for the medical guidance

The clinical guidance on this page follows public authority sources:

Medication storage limits follow each product's manufacturer information (SmPC / patient leaflet) — always defer to the leaflet for your specific product, and to your prescriber for personal advice.

Frequently asked questions

Is it safe to exercise outdoors in Porto today?

Yes — heat is not a limiting factor today (heat score 1.3/10). Usual sun protection applies.

Do I need to worry about storing insulin or Ozempic in Porto this week?

Standard rules apply this week: unopened stock in the fridge at 2–8°C, in-use pens below 30°C away from direct sun.

Who is most at risk from today's conditions in Porto?

Today's Climate Health Score is 6.1/10 (High). Elderly: low · Children: low · Outdoor workers: low · Athletes: low. Led by UV at elevated levels — no extreme single hazard today.

Will tonight be a tropical night in Porto?

No — tonight drops to around 18°C, below the 20°C tropical-night threshold, giving the body a proper recovery window.

When is the heat season in Porto?

Typically July to August, moderate — risk concentrates in rare spike episodes, peaking late July to mid-August. Rare — an exceptional-heatwave phenomenon rather than a seasonal pattern. Today's score at the top of this page reflects live conditions, not the seasonal average.

When is pollen season in Porto?

Grass April–June · olive May–June · plane and birch traces in spring. This page tracks live counts for six species (alder, birch, grass, mugwort, olive and ragweed) and updates them through the day.

When is mosquito season in Porto?

June to September, light dusk nuisance. The live mosquito-activity score on this page places tonight inside that season using temperature and humidity — it measures activity conditions, not disease risk.

Highest-risk cities in Europe today

All cities:

Porto score history — last 30 days

One point per day, refreshed by the daily rebuild. Full archive downloads in the press room.

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Cite this page: “Mobi Doctor — European Climate Health Index, Porto Climate Health Index”, https://www.mobidoctor.eu/health-index/porto/ — updated daily, data CC-BY 4.0 with attribution.