The UK hay fever season can last from late February through to September, depending on which pollens trigger your symptoms. Around 20% of the UK population suffers from hay fever, and knowing exactly when your trigger pollens are at their highest can help you prepare and medicate effectively.
Month-by-Month Breakdown
February – March: Early Tree Pollen
The season begins with hazel and alder trees, which can release pollen as early as late February in milder parts of southern England. Yew and elm follow in March. If you sneeze in early spring while others feel fine, tree pollen may be your trigger.
April – May: Peak Tree Pollen
This is when birch pollen peaks — the most common tree pollen allergen in the UK. Oak, ash, and plane tree pollen also peak during this window. London plane trees are particularly prevalent in cities, making urban hay fever common in April and May.
Late May – July: Grass Pollen Season
Grass pollen is the most common hay fever trigger, affecting around 95% of hay fever sufferers. The season typically begins in late May, peaks in June, and continues into July. This is when pollen counts are at their highest across most of the UK, and when A&E departments see increased asthma presentations.
June – September: Weed Pollen
Weed pollens, including mugwort, nettle, and dock, overlap with the tail end of grass pollen season. They can cause symptoms right through to September, particularly in rural areas.
Regional Differences
The pollen season varies across the UK:
- Southern England: The longest season — can start in February and peak earlier
- Northern England and Scotland: Season starts 2–4 weeks later, with grass pollen typically peaking in late June to early July
- Urban areas: Less grass pollen but more tree pollen (especially plane and birch); pollution can worsen symptoms
- Coastal areas: Generally lower pollen counts, as sea breezes carry pollen inland
Planning Your Treatment
- Use the Met Office pollen forecast to track daily counts from March onward
- Start steroid nasal sprays two weeks before your pollen season begins
- Begin daily antihistamines at least one week before expected symptoms
- Pollen counts are highest in the early morning and early evening — plan outdoor activities for midday when possible
- After rain, pollen counts temporarily drop — a good window for outdoor exercise
Keeping a symptom diary for one season can help you identify your specific triggers and fine-tune your medication plan for the following year.