Households across the UK are being urged to open windows in “short bursts” from Tuesday as humidity and pollen levels rise. While it may sound counterintuitive to open windows when there is a lot of pollen in the air, allowing some ventilation in your home – even for just a brief period – is actually beneficial and can prevent hay fever symptoms from getting worse. The Met Office is forecasting warmer temperatures and sunny spells this week before conditions become more unsettled again by the weekend, which means a spike in pollen levels. Almost all of England is covered by a red ‘very high’ pollen warning today (April 6), with high amounts of birch and ash pollen in the air, and the warnings extend to even more areas on Tuesday.

Very high pollen warnings are in force for the whole of England and Wales on Tuesday, while amber warnings for ‘high’ levels cover Northern Ireland, Dumfries, Galloway, Lothian and Borders, Strathclyde, Central, Tayside and Fife, and Grampian. On Wednesday, red ‘very high’ pollen warnings again cover the whole of England, with levels set to remain ‘very high’ and ‘high’ across England and Wales until Friday.

While NHS advice recommends keeping windows closed “as much as possible” when pollen levels are high to prevent allergens entering your home, it doesn’t mean you shouldn’t open them at all. In fact, it’s recommended that windows are opened in short five to 10 minute bursts in warm weather as this helps to ventilate your home and improve indoor air quality.

If you keep windows sealed shut all day your home can become very humid and high humidity levels create the ideal environment for indoor allergens, like dust mites, to thrive, which, in turn, can make hay fever symptoms worse. Humidity will be high in parts of the UK on Tuesday, with levels set to peak at 75% in London.

The British Allergy Clinic explains: “When humidity is high, pollen grains can absorb moisture from the air, causing them to become heavier and fall to the ground. While this may seem beneficial, certain types of allergens, like mould, thrive in humid conditions. These can produce spores that exacerbate hay fever symptoms, particularly for those sensitive to mould.”

To avoid this problem, it’s recommended that households open windows in short five to 10 minute bursts to allow ventilation and improve the air quality throughout your home. It’s best to do this at times of the day when pollen levels are lower, which is typically in the late morning or early afternoon.

Peter Foldbjerg, Daylight, Energy and Indoor Climate Director at VELUX, told The Express: “You might be tempted to keep windows closed all day to keep the pollen out, but it is important to ventilate nonetheless to avoid additional health issues due to moisture or other indoor pollutants.

“In addition, some patients experience that the hay fever symptoms worsen in humid conditions, making it all the more important to ventilate well.

“To help manage hay fever at home, while keeping a healthy indoor climate, air out rooms in short bursts of 5 to 10 minutes. If you can, open multiple windows at once to increase the air flow. Air out at the right moment. Use a pollen count forecast to monitor the pollen levels in your area, and air out when pollen levels are lowest.”

Ana Zuravliova, Trends Specialist at Blinds Direct, added: “Opening windows at the right times also allows fresh air to circulate through the home regularly, preventing stale air from building up.

“Pollen levels tend to be highest on warm, dry and windy days, particularly around sunrise and again in the early evenings between 5pm and 8pm, therefore it’s best to open windows in the late morning or early afternoon when pollen levels are typically lower, or to keep shutters or blinds partially closed during peak pollen periods to help filter the air.

“For households that struggle with allergies or live in busy urban areas, an air purifier can also help remove particles from the air and create a more comfortable environment for sleeping. Controlling light levels, maintaining good ventilation and keeping fabrics and surfaces clean all contribute to a calmer environment.

“Keeping indoor humidity balanced can also help, as overly damp air can encourage dust mites and mould growth, both of which may affect air quality.”

Other simple measures you can take to improve air quality in your home during hay fever season is to regularly clean surfaces where dust collects, avoid drying clothes on radiators and invest in a dehumidifier.

Ian Palmer-Smith, appliance repair expert at Domestic & General, said: “Lowering the humidity level in your home can not only help keep mould at bay but can also help avoid pesky pollen symptoms.

“When a home has excessive humidity it can increase the amount of dust mites, resulting in an increase in allergens. Ideally, your home should have a relative humidity of below 60%, especially if your household struggles with seasonal allergies.

“Some easy ways to keep your humidity levels controlled include keeping washing machine and dishwasher doors open after each cycle, avoiding drying clothes on radiators, as well as investing in a dehumidifier.”