Pollen Count London Today: Hay Fever Forecast

Tuesday 6 October: the pollen level in London is low (CAMS model forecast). The most common pollen in the air is grass: 0 grains/m³ as a daily mean. The UK pollen season is essentially over; the next one starts with hazel and alder in January to March. Wednesday: low. Thursday: low. Friday: low.

Alder

low · 0

Birch

low · 0

Grass

low · 0

Mugwort

low · 0

PM2.5

8.7 µg/m³

11 µg/m³

5.1 µg/m³

3.8 µg/m³

Max temp

19.3°C

14.4°C

14.3°C

Rain

0 mm

8.1 mm

0 mm

Bar height is the level (low, moderate, high, very high); the number is grains/m³. Tap a day to see its wind on the map.

CAMS model forecast from 6 October at 01:00 BST, weather from the ECMWF model run of 6 October at 07:00 BST. Model values are shown unchanged; this is not a measurement or an official forecast.

Level scale (daily mean concentration, grains/m³; US National Allergy Bureau scale, AAAAI, as the UK has no open national scale): trees moderate from 15, high from 90, very high from 1500; grass from 5, 20 and 200; weeds (mugwort) from 10, 50 and 500. People with hay fever can have symptoms at low levels too.

Hay fever in London

London's hay fever comes in two waves. In spring the trees lead: London plane, which lines many of the city's streets and squares, sheds pollen with birch and oak from April into May, and the centre usually starts a few days ahead of the suburbs because the urban heat island keeps it warmer. From late May grass pollen takes over, much of it carried in from the farmland of the Home Counties on south-westerly winds. On 24 June 1994 a thunderstorm over London on a high grass pollen day sent hundreds of people to hospital with asthma in a single night, one of the best-documented thunderstorm asthma events in the world.

Air quality in London

CAMS forecasts a daily mean of 8.7 µg/m³ of PM2.5 today, below the WHO 24-hour guideline of 15 µg/m³. Air pollution can make hay fever and asthma symptoms worse. Official forecast: Defra UK-AIR.

When plants release pollen

Pollen calendar and where the data comes from

A typical UK year: hazel and alder from January to March, birch from late March to mid-May (the main tree allergen, about one in four hay fever sufferers react to it), grass from mid-May to July, usually in two peaks (early to mid-June and early July), and weeds such as nettle, dock and mugwort from June to September. Scotland runs about two weeks behind the south of England. CAMS does not model hazel, nettle or plane tree.

CAMS (a European ensemble of models, median) computes every hour how much alder, birch, grass, mugwort, ragweed and olive pollen is in the air over Europe, on a grid of about 10 km, four days ahead. On the map, particles start where the model puts pollen in the air today and drift on the ECMWF wind. UK pollen calendar

Pollen count London today: hay fever forecast for 4 days

Hay fever in London

Air quality in London

When plants release pollen

Official sources

Other UK cities