Allergy Calendar for June 2026 in Europe: The Grass Pollen Peak, Worst Days and Where Hay Fever Will Hit Hardest

June is the month when Europe’s allergy season changes character. Tree pollen fades in most regions, but grass pollen becomes the main driver of hay fever from the UK and Ireland to France, Germany, Poland, the Balkans and Scandinavia. Based on the Met Office pollen calendar, the latest late-May UK pollen forecast and SILAM/FMI European pollen modelling, June 2026 should be treated as a high-risk month for anyone sensitive to grass pollen, with additional olive pollen pressure around the Mediterranean and the first weed pollen signals in warmer regions.

Why June is so difficult for allergy sufferers in Europe

For many people, June is not just another month of hay fever season. It is the centre of the grass pollen season. The Met Office states that grass pollen lasts from mid-May until July and has two peaks, with the main peak across England and Wales usually starting in the first two weeks of June. This matters for the rest of Europe as well, because similar meteorological triggers apply across temperate regions: warm days, enough spring growth, low humidity and a light or moderate breeze can rapidly push airborne pollen counts higher.

The latest Met Office regional pollen forecast issued on 27 May 2026 already shows early-season grass pollen becoming established in the UK, with high levels in parts of southern England and Wales by the end of May. This is a clear signal that June should begin with an active pollen background rather than a quiet start.

SILAM/FMI provides 5-day pollen forecasts over Europe with high-resolution atmospheric dispersion modelling. Its European pollen products include grass, birch, olive, alder, hazel, ragweed and mugwort, making it useful for tracking cross-border pollen transport. For June, grass and olive are the most important modelled allergens for most of Europe, while ragweed is generally not the main June threat and becomes much more relevant later in summer.

June 2026 pollen calendar for Europe

Worst countries for pollen allergy in June 2026

The highest June allergy risk is expected in countries where grassland, agriculture, urban parks and warm early-summer weather overlap. The risk is not identical every day, but the broad pattern is clear: western and central Europe usually peak first, while northern Europe often remains active later into the month.

United Kingdom and Ireland

The UK enters June with grass pollen already rising, especially in England and Wales. According to the Met Office seasonal pattern, the first two weeks of June are usually the most important grass pollen window across England and Wales. London, the South East, the South West, the Midlands, Wales and eastern England should be watched particularly closely during dry and breezy spells. Ireland may see a similar grass pollen build-up, especially after warm, sunny intervals following spring rainfall.

France, Belgium and the Netherlands

France, Belgium and the Netherlands are likely to see widespread grass pollen risk through much of June. Northern France, the Paris Basin, Belgium and the Dutch lowlands can experience very high exposure when dry air, sunshine and moderate wind combine. In southern France, grass pollen may overlap with olive pollen and other Mediterranean allergens.

Germany, Switzerland, Austria and Czechia

Central Europe is one of the key June allergy zones. Germany, Switzerland, Austria and Czechia have large grassland and agricultural areas, and pollen can remain high for many consecutive days if the weather turns settled. Urban patients may feel symptoms strongly too, because pollen mixes with air pollution and irritates already inflamed airways.

Poland, Hungary, Slovakia and the Balkans

Eastern and south-eastern Europe should prepare for a strong grass pollen month, with local peaks during hot, windy periods. In Hungary, Serbia, Croatia, Romania and Bulgaria, June can bring a mixed pattern: grasses dominate, but early weed pollen may gradually begin to appear toward the end of the month. Ragweed is not yet the main seasonal allergen in June, but sensitised patients should start monitoring forecasts before the late-summer season.

Scandinavia and the Baltic states

Denmark, southern Sweden, southern Norway, Finland, Lithuania, Latvia and Estonia often see their grass pollen pressure rise later than western Europe. That means the second half of June can become especially difficult. Birch pollen may still linger in cooler northern areas at the beginning of the month, but grass becomes increasingly important as temperatures rise.

Mediterranean Europe

Spain, Portugal, southern France, Italy, Greece and parts of the western Balkans face a different June allergy profile. Grass pollen remains important, but olive pollen can be a major trigger, especially in olive-growing regions. Dry heat can reduce some pollen release if temperatures become extreme, but before that point warm breezy days may bring intense exposure.

How weather will affect allergies in June

Weather is the switch that turns pollen risk from moderate to severe. A day with grass in flower does not automatically become a bad allergy day. The worst symptoms usually develop when the air is warm, dry and breezy. The Met Office notes that, for grass pollen, maximum temperatures around 18–28°C can produce high counts when the day is dry, humidity is low and there is a gentle breeze.

Rain usually lowers airborne pollen for a time because it washes particles from the air. Heavy rain early in the day can keep counts suppressed for longer. However, there are two important exceptions. First, if rain is followed by sunshine and warmth, grasses can release a fresh pollen burst. Second, thunderstorms can sometimes worsen symptoms because pollen grains may rupture into smaller fragments that penetrate deeper into the airways. People with asthma should be especially careful on hot, humid, stormy days.

Wind is another major factor. Even if your city is not surrounded by meadows, grass pollen can travel from rural areas into towns. Pollution may make symptoms more irritating in urban centres, which is why hay fever in cities can feel worse than the pollen count alone suggests.

Main allergens in June 2026

How pollen allergy manifests in June

Grass pollen allergy, commonly called hay fever or allergic rhinitis, often causes sneezing, a runny or blocked nose, itchy red or watery eyes, an itchy throat, coughing, headaches and fatigue. Symptoms can last for weeks and may be mistaken for a cold, but hay fever usually follows pollen exposure and often worsens outdoors, in parks, near cut grass or on warm windy days.

Patients with asthma need to be more cautious. Allergic rhinitis and asthma often coexist, and pollen exposure can trigger coughing, wheezing, chest tightness or shortness of breath. If breathing symptoms appear, the problem is no longer just “annoying hay fever” and medical advice is important.

Cross-reactive foods during grass pollen season

June is also the month when pollen-food allergy syndrome may become more noticeable. People allergic to grass pollen can react to raw plant foods because some proteins resemble pollen allergens. According to AAAAI and ACAAI, grass pollen sensitivity may be associated with reactions to celery, melons, oranges, peaches and tomatoes. These reactions usually appear as itching or tingling in the mouth, lips, tongue or throat shortly after eating raw foods.

Most pollen-food reactions are mild and local, but warning signs include throat tightness, difficulty swallowing, wheezing, widespread hives, vomiting or dizziness. Reactions to nuts or symptoms beyond the mouth should be discussed with an allergist.

Practical advice for allergy sufferers in June

Track pollen forecasts daily, especially if you are travelling across Europe. SILAM and national pollen services are useful because the risk can change quickly after rain, wind shifts or sudden warming. On high pollen days, reduce outdoor activity during peak periods, keep windows closed in the morning and evening, and use car pollen filters where possible.

After being outside, shower, wash your hair and change clothes to remove pollen. Do not dry laundry outdoors during high-count periods because fabric can collect pollen. Wraparound sunglasses, a wide-brimmed hat and a mask can reduce exposure when you cannot avoid outdoor activity.

Medication works best when used early and consistently. Non-drowsy antihistamines may help itching, sneezing and watery eyes. Steroid nasal sprays are often more effective for persistent nasal congestion, but they need correct technique and regular use. If symptoms continue despite pharmacy treatment, or if asthma symptoms worsen, seek medical advice.

Travel advice: where June allergies may feel worse

If you are planning a June trip, avoid assuming that a coastal destination is automatically safe. Coastal breezes can lower local grass pollen in some places, but Mediterranean regions may have olive pollen and other local allergens. Mountain valleys may trap pollen during calm weather. Rural holidays, camping, vineyards, meadows and countryside cycling can bring higher exposure than city breaks, especially during grass cutting and haymaking.

For city travellers, the main issue is the combination of pollen and pollution. London, Paris, Milan, Madrid, Berlin, Warsaw and other large European cities can feel difficult during dry stagnant weather even when official pollen levels are not extreme.

Forecast confidence and limitations

This June 2026 allergy calendar is a forecast-based risk outlook, not a clinical diagnosis and not a fixed daily pollen measurement. Met Office operational pollen forecasts cover the UK for five days ahead, while SILAM/FMI provides short-range European model forecasts. For a full month, the most reliable approach is to combine seasonal pollen biology, current late-May signals and weather-dependent risk windows. Exact daily peaks will depend on rainfall, wind, temperature and thunderstorm timing.

FAQ

What is the main allergy in Europe in June?

Grass pollen is the main June allergen across most of Europe. Olive pollen is also important in Mediterranean countries.

When is grass pollen highest in June?

In western and central Europe, the first half of June is often the most difficult period. A second high-risk wave can occur in the second half of the month, especially in northern and eastern Europe.

Does rain reduce pollen allergy symptoms?

Rain usually lowers airborne pollen temporarily. However, if warm and windy weather returns quickly, pollen levels can rebound. Thunderstorms may worsen symptoms in some people.

Is ragweed a major problem in June?

Ragweed is usually not the main June allergen in Europe. It becomes much more important later in summer and autumn, especially in parts of eastern and south-eastern Europe.

Can grass pollen cause food reactions?

Yes. Some people with grass pollen allergy may react to raw tomato, melon, peach, celery or orange. This is known as pollen-food allergy syndrome or oral allergy syndrome.

Sources and methodology

This outlook is based on Met Office pollen guidance and 5-day UK pollen forecasts, SILAM/FMI European pollen modelling, and clinical advice from NHS, Allergy UK, AAAAI and ACAAI. The calendar separates observed short-range signals from seasonal risk expectations because pollen peaks depend strongly on weather.