Hayfever season doesn't fully end in summer. Weed pollens (like nettle and mugwort) linger into early autumn, and as the weather cools two indoor problems grow: mould spores from rising damp and condensation, and trapped pollution because we open windows less and start heating.
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Shop the UK store → See all kitsThe autumn indoor cocktail
- Late weed pollen on dry, breezy days.
- Mould spores as condensation returns to cold external walls — common in London's older flats.
- Combustion particles as heating and wood burners fire up.
Keeping it clean
Ventilate briefly but effectively to manage moisture, fix damp at the source, and run a purifier to clear spores and particles. MERV-13 handles both pollen and 2–20 micron mould spores.
Frequently asked questions
Does hayfever continue into autumn?
Weed pollens can persist into early autumn, and mould spores from damp rise as the weather cools — so symptoms often continue for sensitive people.
Why does indoor air get worse in autumn?
Windows close, heating starts and damp increases, so pollution and mould spores build up indoors.