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Should I open the windows in Lisboa right now?

Live decision for Lisboa. Updated every 30 minutes.

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Ventilation guide for Lisboa

Lisboa has a subtropical Atlantic climate — warmer and sunnier than northern oceanic cities but tempered by consistent Atlantic airflows that moderate heat extremes. Summers are warm (25–30°C) and drier, winters mild (10–15°C) and wet. The combination of sunshine and Atlantic breeze makes for genuinely good ventilation conditions across most of the year. Spring and autumn — April through June and September through October — are the best seasons: outdoor temperatures of 16–22°C, moderate humidity, and clean air from Atlantic wind systems.

Summer management in Lisboa: on the hottest inland days, the morning ventilation window (6–9 AM) is effective, while late afternoons may be too warm for passive cooling unless a sea breeze is present. The Atlantic acts as a natural temperature regulator — coastal positions benefit from consistent onshore breezes that urban inland areas don't receive. Air quality in Atlantic-facing cities is among the cleanest in Europe, with persistent airflows flushing pollutants. Occasional peaks occur during extended calm anticyclonic periods in winter, when traffic emissions accumulate without dispersal. OpenWindow.live identifies these infrequent but genuine air quality events.

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Frequently asked questions

When is it best to open windows in Lisboa?

In Lisboa, the best ventilation times are typically early morning (5–8 AM) and late evening (after sunset) when outdoor temperatures drop below indoor levels.

Is it safe to leave windows open at night in Lisboa?

Yes, in most weather conditions. Open windows can drop indoor temperature by 2–5°C in 30 minutes if outdoor air is cooler. Check the live recommendation above for tonight.

What outdoor humidity is too high for ventilation?

Above 80% humidity, opening windows can make indoor air feel sticky. Combine with dehumidifier or wait for drier hours.