Mould spore season UK
Mould spores usually peak from July to September and can trigger asthma or hay fever-like symptoms.
Countdown
35
days to go
Next date
Saturday, 15 August 2026
2026 mould spore peak period
Get a reminder 7 days before Mould spore season UK
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Upcoming dates
| Event | Date | Countdown | Region / notes |
|---|---|---|---|
| 2026 mould spore peak period | Saturday, 15 August 2026 | In 1 month | Commonly July-September |
| 2026 mould spore season eases | Wednesday, 30 September 2026 | In 3 months | UK |
| 2027 mould spore season rises | Thursday, 1 July 2027 | In 1 year | UK |
Mould spores are an overlooked seasonal trigger. Outdoor levels often rise in late summer and early autumn, especially in damp weather and around decaying vegetation or harvest activity. For some people they can cause hay fever-like symptoms or worsen asthma. If pollen counts are falling but symptoms continue, check mould spore forecasts and follow medical advice for asthma or allergy treatment.
health
Allergy and asthma support
Verified 14 May 2026
Questions
When is mould spore season?
Outdoor mould spores often peak from July to September in the UK.
Can mould spores cause hay fever symptoms?
Yes. They can cause similar symptoms and may also worsen asthma in sensitive people.
What weather increases mould spores?
Damp weather and decaying vegetation can increase outdoor mould spores.