GISMETEO: Allergy Prediction in Gismeteo: Allergens, Map and Pollen Index – About the Weather

Pollination, or allergic fever, is a common seasonal allergic disease. According to statistics, every fifth person suffers from this disease to some degree.

Annual exacerbations of plant pollen allergy occur almost simultaneously, with small shifts due to seasonal differences, and are associated with flowering plants. Of the wide variety of species growing on the planet, only a few dozen have a strong allergenic effect.

The list of the most aggressive plants can be divided into three groups.

The first group is the wind pollinated deciduous trees and shrubs. Among them are birch, alder, hazelnut, ash, oak, maple. All these species are dusty mainly in spring.

The most dangerous is the birch. At the peak of flowering, just one earring produces up to 5 million pollen grains. Birch pollen has good volatility and permeability. Dust particles with a diameter of 20-30 microns (0.02-0.03 mm) are carried by the wind over long distances (up to 1000 km) and, penetrating the airway, cause allergic reactions in millions of people.

Among the conifers, spruce and pine are dusty. But their pollen is less allergenic. Due to its large size (80-100 microns), it is retained by the epithelium.

Cereal pollen – the second most important plant allergen. Cereals are wild (meadows) and cultivated. Wild plants include: hedgehog, bluegrass, Timothy, fescue, couch grass, ryegrass, foxtail. Cultivated cereals are rye, wheat, millet, corn, rice, barley. In central Russia, the flowering period of cereals falls in the first half of summer. Most pollen is produced from: Timotheos, rye, fesua and rye.

The third group of allergenic plants is represented by mourning widow clothes. Includes: absinthe, quinoa, plane tree, ragweed. Weeds bloom in the second half of summer – early autumn. From the third group, ragweed is the most dangerous. Just a few pollen grains can cause severe allergic reactions.

Grass pollen is less volatile than tree pollen. With an average size of 30-40 microns, it is transported in several hundred meters.

What and where do we anticipate?

We predict the pollen concentrations of the most common and aggressive plant allergens: birch, grass and ragweed.

The forecast area has expanded to cover most of Russia, as well as many neighboring countries. The prediction of pollen concentration can be seen both on the pages of the settlements and on a map that clearly shows the spread of allergens.

For the area shaded in gray, while the forecast is not available

pollen scale

Low Moderate High Too high end
Birch 1–30 31–200 201–1000 1001–5000 > 5000
Cereals 1–10 11–50 51–200 201–1500 > 1500
Ambrosia 1–7 8–30 31–100 101–1000 > 1000

Which concentration is dangerous?

High concentration is considered dangerous. Each type of allergenic vegetation has its own criteria for high concentration.

The risk ratings presented in the myth on the site are typical for most people with allergic rhinitis. However, it must be borne in mind that each individual reacts to allergens in a purely individual way. Therefore, the maximum allowable concentration for each will be different.

How does the weather affect pollen?

The amount of pollen depends largely on the weather. Rain, wind, temperature and sun affect the production, distribution and deposition of pollen.

The sun

Sunlight increases pollen production. The more sunlight, the more active the photosynthesis plant is and the more pollen the plants produce.


Rain significantly reduces the amount of pollen. But the question is how much rain and when. For example, heavy rainfall that started in the morning is likely to keep pollen levels low throughout the day. At the same time, intermittent rains in the afternoon will have a much smaller impact. However, occasional rainy days during the month usually lead to a harsher season overall.


A weak wind is not able to carry and disperse the pollen. A strong wind blows the pollen, lifts it into the atmosphere and thus reduces the concentration. Moderate wind is the main carrier of pollen, including long distances. As a result, pollen imported from other areas can cause allergic reactions long before the local plants become dusty.

Air temperature

Herbaceous plants dust best at temperatures from +18 to +28. Trees prefer an area of ​​+13 … +15 degrees. At temperatures above +28, pollen production stops.

Air humidity

In dry weather with low relative humidity, pollen concentrations increase. However, if the whole season is dry, then the plants reduce pollen production.

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