Pollen allergies in Ile-de-France: the new bulletin, causes and recommendations to adopt

Île-de-France is a dense and exposed region, and the end of the Réseau national de surveillance aérobiologique (RNSA) has given way to a new tool signed Atmo France. In this period of spring pollen peaks, focus on this new tool, the local aggravating causes and the good habits to adopt.

Do you have an itchy nose and sneeze every time you step outside? If you're suffering from a pollen allergy, this is unfortunately normal, given the circulation of these little airborne elements, and it's not over yet, as these blooms will continue throughout April and May. The birch trees will give way to the grasses, which will become stronger at the beginning of May.

In France, nearly 30% of adults and 20% of children over the age of 9 suffer from pollen-related allergies. This rise is attributed to several aggravating factors: global warming, which lengthens pollen seasons and intensifies pollen production; air pollution, which accentuates their allergenic power; andurbanization, with the choice of plant species that are often highly allergenic, such as birch and plane tree.

In Île-de-France, a particularly exposed region, pollination periods are longer and pollen concentrations higher, making symptoms more frequent and intense. Projections estimate thatone person in two could be allergic by 2050, according to the WHO. On April 2, 2025, the Atmo France federation inaugurated a new pollen index, intended to replace the vigilance map of the RNSA, which has gone into receivership. So, if you've tried to consult the bulletins of the world's first pollen-index website, don't be surprised if it no longer shows anything. Atmo's new tool now allows you to consult the concentration of six types of pollen, with forecasts for D+1 and D+2, commune by commune.

Why has RNSA ceased its activities?

For three decades, the French National Aerobiological Monitoring Network (Réseau national de surveillance aérobiologique - RNSA) was responsible for measuring the risk of pollen allergies. Its system, well known to allergy sufferers, relied on manual sensors scattered across France. However, in March 2025, the association was placed in receivership, following a damning report by the IGAS and IGEDD, denouncing management anomalies, a lack of transparency and technical shortcomings. As a result, the French government withdrew its subsidies, bringing the pollen bulletins to a halt.

What does Atmo France's new index offer?

The new system, called the " pollen index ", differs from its predecessor in that it measures the actual concentration of pollen in the air, rather than the estimated allergic risk. The tool is based on artificial intelligence that crosses station readings, weather data and satellite sources such as the Copernicus program. It covers six types of pollen: alder, birch, grass, ragweed, mugwort and olive. Two major absentees - cypress and hazelnut - will be included from 2026.

The pollen index operates on a six-level scale, inspired by the air quality index. Each level is associated with a color and a degree of allergic risk:

Very low
Low
Moderate
High
Very high
Extremely high

As soon as the "high" level is reached, a pollen peak is triggered. This threshold marks sufficient exposure to cause or aggravate allergic symptoms in sensitive individuals.

Where can you consult this index?

The pollen index is available free of charge:

On the officialAtmo France website
By email subscription, with an alert sent directly to the user depending on the commune.

This local, real-time information allows you to better adapt your daily habits.

Technology based on artificial intelligence

The pollen index calculation is based on an innovative machine learning methodology developed by Atmo France. It is based on eight years of pollen surveys combined with precise meteorological data. Spatialized data from the Copernicus program is used to generate forecasts for every point in the country, including the Paris region.

This evolutionary system will gradually adjust itself, gaining in precision over time, thanks to data enrichment and feedback from the field. It represents a major step forward in monitoring air quality in relation to respiratory allergies.

Why are pollen allergies exploding?

Theincrease in the number of cases can be explained by several interrelated phenomena:

Climate change: milder temperatures mean earlier flowering and longer pollination. Certain plants, such as grasses and birch, also produce more pollen.
Atmospheric pollution: this modifies the structure of pollen, making it more aggressive and amplifying symptoms.
Modern lifestyle:excessive hygiene, indoor living and a processed diet disrupt immunity.
Urban plantations: cities favor robust but highly allergenic trees such as plane trees or male birches.

Which pollens are the most allergenic in the Paris region?

Here is a list of the main allergenic pollens in the Île-de-France region, along with their approximate pollination period.

Hazel: January to March
First source of allergy of the year, from the end of winter.
Alder: February to March
Present in late winter, often at the same time as hazelnut.
Ash: March to May
Contributes to early spring allergies, with a peak in April.
Birch: March to April
Widespread in the parks and streets of Paris, this is one of the most allergenic pollens. It is currently peaking.
Plane tree: mainly in April
Very common in urban areas, particularly in Paris, it releases irritating pollens.
Grasses: May to July, with a peak in June
These herbaceous plants are responsible for the majority of seasonal allergic rhinitis.
Mugwort: August
Summer pollen, to watch out for in cases of specific sensitivity.
ragweed: late July to October
Less widespread than in the Rhône Valley, but on the increase in the Île-de-France region, this plant is extremely allergenic.

Birch, ubiquitous in urban parks, is particularly dreaded. It is currently in the middle of its pollen release phase. Next come grasses, responsible for the majority of springtime allergic rhinitis.

What can you do to limit allergies?

In case of allergy, remember to follow the recommendations of Sante Publique France and the French Ministry of Health.

Before going out

Consult the daily pollen index provided by Atmo France for your commune (forecasts on D, D+1 and D+2).
Avoid outdoor activities during pollen peaks, especially when the weather is dry, hot and windy.
Prefer outings early in the morning or after 7pm, when pollen concentrations are generally lower.
Wear wraparound sunglasses to limit pollen contact with the eyes.
Wear a surgical or FFP2 mask if you are very sensitive, especially during peak pollen periods.

Back home

Change your clothes immediately to avoid spreading pollens indoors.
Shower and wash your hair in the evening, especially if you've been outdoors.
Don't dry your laundry outside, as pollen settles easily.

Inside your home

Keep windows closed during the day, especially during periods of high pollen risk.
Ventilate briefly and outside peak periods, early in the morning or late at night, if necessary.
Install an air purifier with a HEPA filter, especially in the bedroom.
Regularly vacuum floors and fabrics (curtains, sofas, carpets) with a HEPA-filtered vacuum cleaner.
Clean ventilation grilles and air-conditioning filters often.
Avoid smoking indoors, as it aggravates allergic symptoms.

Good luck, then, to all those allergic to pollens. Don't forget to consult the new bulletin to stay informed and adopt the right precautions, and consult a doctor in the event of an attack. During this period, avoid outdoor sports and protect yourself.