Pollen and whether to open the windows

Pollen only changes window advice if you said you are sensitive. If you are not, temperature still leads.

That is deliberate. Closing for pollen on a 30 °C indoor evening, for someone who is not bothered by it, would trap heat for no gain. The app asks during setup, and you can change the answer later in Your home.

How the advice changes

On high pollen days, sensitive people get a smaller opening. On very high days, windows stay closed unless the room is already dangerously hot. That trade-off is the same idea as dirty air versus indoor heat.

Pollen maps in Ventilate cover Europe (CAMS). Elsewhere the pollen row may stay empty. Missing data does not close your windows.

Grass, birch, and ragweed peaks do not land on the same week in Paris, Madrid, and Berlin. The rule is the same: only override temperature if you asked the app to. See heatwave playbooks by city.

The pollen checklist

• Set pollen sensitivity in onboarding or Your home
• High pollen: crack a window rather than open wide
• Very high pollen: keep closed unless indoor heat is severe

This is not medical advice. If you have asthma or a diagnosed allergy, follow your clinician and your local pollen alerts.