Action first
How to ventilate a house at night
Short answer
Open safe windows after outside becomes cooler than inside and create a clear route for air through the home.
What to do
- ✓Check that the outside air is cooler.
- ✓Open secure windows on different sides or levels.
- ✓Use an outward-facing fan at one opening if airflow is weak.
- ✓Close up again before outdoor temperatures rise.
Why it works
This advice follows UK Health Security Agency guidance and the underlying principles of night ventilation and airflow.
Important exceptions
Safety, health, weather and the design of your home can change what is appropriate. Stop if an action makes conditions worse.
Related guides
Sources & evidence
Reviewed 2026-08-21
- UK Health Security Agency: Beat the heat: keep cool at home checklist ↗
Supports: Shading, ventilation, reducing indoor heat and protecting people at higher risk.
official guidance · Accessed 2026-08-21