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Mosquito Forecast: What to Expect Summer 2026 in Europe

Mosticare Editorial4 May 20267 min read
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Conditions across Europe are favourable for mosquitoes in summer 2026. Aedes albopictus is established in 369 regions across 16 countries, the 2025 chikungunya outbreak showed that local transmission can reach scale, and the 2024 dengue record reset expectations. This is the region-by-region outlook, from the Mediterranean core to the northern watch zone, with a practical preparation checklist for residents and travellers.

Data from the ECDC, recent outbreak trends and climate projections allow an assessment of the 2026 mosquito season in Europe. This article sets out the starting conditions, the regions most likely to be affected, and the steps residents and travellers can take.

The Baseline: Where We Start

Conditions for summer 2026 favour mosquitoes. The tiger mosquito is established in 369 regions across 16 countries. In 2025, nearly 800 locally acquired chikungunya cases were recorded in France and more than 380 in Italy; local transmission at that scale is now established on the continent. In 2024, 304 locally acquired dengue cases were recorded on the mainland, a figure that exceeded previous years.

A Vax-Before-Travel analysis of whether dengue will continue spreading in Europe in 2026 concluded that transmission is likely to continue.

High-Risk Regions: Summer 2026

Tier 1: Highest risk, the Mediterranean core

Southern France, northern Italy, and the broader Mediterranean coast face the most significant mosquito-borne disease risk this summer. These areas combine dense, well-established tiger mosquito populations with high volumes of international travel from dengue and chikungunya-endemic tropical countries.

Research cited by ScienceDaily identifies southern France and northern Italy as the parts of Europe most likely to be affected by dengue. The factors are favourable climate, stable mosquito populations, and high traveller volumes.

ECDC runs seasonal surveillance for chikungunya virus disease in the EU/EEA. Based on the 2025 pattern, multiple simultaneous outbreak clusters are possible.

Spain's Mediterranean coast and the Balearic Islands and Malta sit in the same tier, alongside Greece and Croatia, all with established populations and high tourist volume.

Tier 2: Elevated risk, the expanding range

Central France is now squarely in the elevated risk zone following the 2025 detection of local transmission in regions as far north as Alsace. Germany's Rhine Valley and southwestern regions host established mosquito populations, and cities like Frankfurt are flagged by the European Commission as at risk.

Austria around Vienna, Hungary, Slovenia, and Slovakia represent the central European expansion zone. The ECDC's June 2025 distribution update recorded the tiger mosquito as newly established in Slovakia. Populations there are growing but have not reached the density seen in the Mediterranean.

Belgium's southern regions and areas of Portugal are also in this tier, with established populations and growing risk profiles.

Tier 3: Emerging risk, the northern watch

Southern England, the Netherlands, and Luxembourg are in the watch zone. Climate projections indicate growing suitability, and the proximity of established populations in northern France and Belgium means that introduction events are increasingly likely.

Southern Scandinavia and the Baltic states remain in the longer-term projection category, but warming trends mean they should not be dismissed from planning considerations.

Disease Outlook for 2026

Based on the trajectory from 2024 and 2025, three mosquito-borne diseases warrant attention in Europe this summer:

Dengue is expected to see continued locally acquired cases across the Mediterranean, potentially exceeding the 2024 figure of 304 cases. The FlaviVaccine project has described the rising arboviral threat across Europe.

Chikungunya demonstrated in 2025 that it can sustain large-scale local transmission in Europe. Whether 2026 sees a repeat or escalation depends on the volume of imported cases during the early transmission window. The WHO's chikungunya global situation report documented 445,271 cases globally between January and September 2025, maintaining a large reservoir of potential imported cases.

West Nile virus is transmitted by Culex mosquitoes rather than Aedes. It has been rising across southern and eastern Europe and should be monitored as a separate but related threat.

The Early Season Signal

One factor to watch is whether the 2026 mosquito season starts earlier than normal. The ECDC noted in 2025 that rising temperatures, longer summer seasons and milder winters are expanding the tiger mosquito's range across Europe. A warmer 2026 would extend the overall transmission window and increase cumulative risk.

Spring temperature data across southern and central Europe will provide the first signal. If March and April temperatures run above average, expect earlier mosquito emergence and a longer season ahead.

Preparation Checklist: Summer 2026

Whether you live in an established mosquito zone or plan a Mediterranean holiday, these steps reduce exposure.

For Residents in Established Zones

  • Inspect and repair all window and door screens before May
  • Walk your property perimeter and remove all standing water sources
  • Set a weekly reminder to check for new standing water after rainfall
  • Stock personal repellent products (DEET, icaridin, or IR3535-based)
  • Learn the symptoms of dengue and chikungunya: sudden fever, severe joint pain, rash
  • Know your local reporting system for mosquito sightings or suspected cases

For Residents in Expanding Zones

  • Install window screens if you do not already have them
  • Begin removing standing water around your home in April
  • Check the ECDC mosquito maps for your region's current status
  • Prepare personal repellent for evening outdoor activities from May onwards
  • Inform your household about the changing mosquito landscape

For Travellers to Mediterranean Europe

  • Pack personal mosquito repellent as a non-negotiable travel item
  • Choose accommodation with window screens or air conditioning
  • Wear light-coloured, long-sleeved clothing during peak mosquito hours
  • Be aware that tiger mosquitoes bite during daylight hours, not just at dusk
  • Seek medical attention for fever, joint pain, or rash after returning from an affected area
  • Report symptoms to your healthcare provider and mention your travel history

Looking Ahead

The 2026 outlook is serious, and it is manageable. Institutional surveillance, public awareness and individual protective action together reduce both the nuisance and the health risk.

The main risk is complacency: assuming that mosquito-borne disease affects somewhere else. Mosquito-borne transmission now occurs in parts of Europe. Households that remove standing water, repair screens and use repellent reduce their exposure.

Sources

Sources & citations
  1. ECDC, Aedes albopictus current known distribution (June 2025); 369 regions across 16 countries
  2. ECDC, Mosquito maps, surveillance and disease data
  3. ECDC, World Mosquito Day 2025: Europe sets new records for mosquito-borne diseases
  4. Nature, Mosquito-borne diseases surging in Europe (2024 dengue record, 304 cases)
  5. PMC, Europe faces multiple arboviral threats 2025 (nearly 800 locally acquired chikungunya cases in France and more than 380 in Italy, 2025)
  6. European Commission, European cities at risk of dengue, Zika and chikungunya (Jan 2026)
  7. ScienceDaily, Areas of Europe most at risk from dengue (southern France, northern Italy)
  8. Vax-Before-Travel, Will dengue continue spreading in Europe in 2026?
  9. FlaviVaccine, A hotter, riskier Europe: rising mosquito-borne disease threats
  10. WHO, Chikungunya global situation report (445,271 cases globally, January to September 2025)
  11. ECDC, seasonal surveillance for chikungunya virus disease in the EU/EEA for 2026
  12. Santé publique France, chikungunya, dengue and Zika in mainland France, 2025 review: first local transmission in Nouvelle-Aquitaine, Grand Est and Bourgogne-Franche-Comté

Correction policy: if any fact above is shown to be wrong, we will amend it in place with a dated correction notice. Contact corrections@mosticare.org.

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