Experts share the regions that will see high levels of tree pollen as allergy sufferers are advised to take caution during today’s warm spell of weather
Hay fever sufferers are preparing for a challenging time as Britain anticipates the warmest day of the year. Pleasant consecutive days of sunshine have graced the UK, and the Met Office forecasts point to temperatures soaring above average on Thursday, coinciding with the spring equinox.
It is Southern England that will bathe in the most warmth, with London set to experience an impressive 20C, nudging past the previous record for 2025’s hottest day by 0.3C. Crosby in Merseyside currently holds 2025’s warmest temperature so far, having reached 19.7C on March 9.
The spell of warm weather came as a relief after a notably long and bleak winter, but for those battling hay fever, the sunny spell brings with it the downside of increased tree pollen levels. According to the University of Worcester’s latest weekly pollen forecast, high levels of alder pollen are expected to persist for another week, posing a “high risk during mild, dry weather”.
While temperatures could climb to 17C in Liverpool and 18C in Manchester in the north of England, there will be a moderate risk of hazel pollen, although it is dissipating in other areas. Moving through April into May, Wales, South East England and both the East and West Midlands are projected to face a high risk of birch pollen, per the university’s predictions.
The South East is bracing for an average of 14 days of heightened birch pollen levels in the upcoming months. The West Midlands is forecast to experience 13 high-risk days, according to recent data. Wales and the East Midlands are predicted to face 10 and eight such days respectively.
Worcester’s current pollen forecast extends until March 21, with the Met Office anticipating more unsettled weather thereafter. By March 25, some areas in southern England could see temperatures dip to as low as 10C, while in Scotland, the mercury may only reach 9C.
In addition, this week will mark a rise in fungal spore levels, with an increase in aspergillus and penicillium spores. These spores, commonly found in soil, compost, and decaying foliage, pose potential health risks for individuals with respiratory issues.
While the grass pollen season is yet a few weeks away, hay fever sufferers must grapple with the tree pollen season which can begin as early as January, according to expert sources. Specifically, the university’s website advised: “Some people are allergic to early flowering trees such as hazel and alder which start producing pollen from January until late March.
“The main tree pollen season (mainly birch and then oak pollen) affects more sufferers and runs from late March until early June. The main grass pollen season overlaps with the main tree pollen season and runs from late April to July.”
The season for grass pollen is expected to begin in April, typically peaking in summer. However, the current warm spell caused concern among the university’s experts, who warn that tree pollen levels may remain high for several weeks.
Senior pollen forecaster Dr Beverley Adams-Groom told the BBC: “Trees that produce allergenic pollen in the UK tend to have alternating high and low years of severity – this year is a high year. Mild, dry weather with breezes provides the best conditions for pollen release and that is what is forecast for the next week or so.”
Common hay fever symptoms include “excessive sneezing, runny nose, itchy eyes and an itchy throat and palate and usually occur outside and in episodes”, according to the university. Comparing symptom onset with local pollen forecasts can help identify the cause.
The charity Allergy UK recommends reducing pollen exposure by:
- Wear a mask, wraparound sunglasses and a hat with a large peak or brim when outdoors to keep pollen allergens out of your eyes, face, and hair
- Shower, wash your hair and change your clothing, especially before bed if you have been out for long periods
- Avoid outdoor activities that expose you to pollen, such as mowing lawns or raking leaves
- Keep windows closed at home and in the car, especially in the early morning and evening, when the pollen count is higher
- Avoid drying clothes/linen outside as pollen can be brought inside on the clothes
- Wipe pets’ coats with a damp microfibre cloth to remove pollen when they have been out
If symptoms persist after a few weeks, people must speak to their GP.
