Could it ruin your trip? Blue Dragons and Flying Ants: How to Navigate a "Dangerous Summer" - Jellyfish, Smoke Damage, and Aerial Swarms

The vacation season of 2025 is not just about "getting caught in the rain." On the coasts of Spain, the highly venomous sea slug known as the "blue dragon" has appeared, while in the Caribbean, record amounts of foul-smelling sargassum have washed ashore. In the U.S., a widespread windstorm known as a "derecho" sweeps through, and the skies over the UK are darkened by "flying ants." In Svalbard, Norway, the sun does not rise during the polar night, in northeastern Australia, it's the season of venomous jellyfish, and in northern Thailand, it's the "slash-and-burn season" with smoke pollution.
This article summarizes the latest trends of each phenomenon, their impact on travel logistics, and reactions on social media, based on a feature by InfoMoney (August 24). InfoMoney

1) Appearance of the "Blue Dragon" in Spain: The Enchanting Blue You Shouldn't Touch

Around August 20, a vivid blue sea slug, Glaucus atlanticus (commonly known as the "blue dragon"), was spotted in the Guardamar del Segura area of Alicante, Spain, leading to a temporary ban on swimming. Although small at 3-4 cm in length, it absorbs and intensifies the venom of jellyfish (such as the Portuguese man o' war) and can cause severe pain and vomiting in humans. The local government raised red flags and increased monitoring. The beach was conditionally reopened the next day with continued vigilance, but reports of additional sightings have persisted. The TimesPeople.comwww.20minutos.es - Últimas Noticia

Social Media Reactions
Local governments and weather accounts issued warnings on X and Facebook. Posts from local users urging people not to touch the beautiful-looking creature spread widely. X (formerly Twitter)Facebook

Impact on Travel and Measures
・When the red flag is raised, swimming is prohibited. Even if found on the beach, do not touch with bare hands. If stung, rinse with seawater, and seek medical help if symptoms occur. Spain in EnglishCadena SER

2) Sargassum in the Caribbean: 2025 is "Record-Breaking"

The sargassum (brown seaweed) influx in 2025 has reached record levels according to satellite observations. April saw levels surpassing the highest from 2011–2024, with reports of a 40% increase in some areas compared to 2022. Beaches are covered in brown seaweed, and the ammonia and hydrogen sulfide odors diminish the quality of stay. Long-term exposure is also noted to pose respiratory risks. NBC 6 South Floridastthomassource.comDCNA

Social Media Reactions
On TikTok and Facebook, travelers lamenting "the sea is brown despite coming all the way here..." and local authorities' "before and after cleanup" videos are prevalent. As sea conditions vary by island and bay, more voices are urging checking the latest beach information in advance. Facebook

Impact on Travel and Measures
・Avoid leeward side beaches of seaweed belts. Check the cleanup systems of hotels and local governments in advance. Be prepared for odors and insects (which may occur). Telegraph

3) "Derecho" in the U.S. Midwest and Beyond: Unpredictable Widespread Windstorms

A "derecho" is a long-lived, widespread, and straight-line wind event caused by a massive thunderstorm system moving in a straight line. It is classified when the wind damage path is over 240 miles (about 400 km), and wind gusts of 58 mph (about 93 km/h) or more are observed over a wide area. It is characterized by blowing for hours along the direction of movement. Huron Daily TribuneYahoo! News

Social Media Reactions
Posts on X by U.S. storm chasers and residents are filled with photos of arc-shaped "bow echoes" and wall-like shelf clouds. Reports like "It's not a tornado, but the entire town is full of fallen trees" are also common. Wikipedia

Impact on Travel and Measures
・Install a warning app and immediately stop outdoor activities. Do not park rental cars under trees. Prepare for power and communication outages with mobile batteries and water. InfoMoney

4) UK's "Flying Ant Day": The Day the Sky Looks Black

From mid-June to September, swarms of queen ants take flight across various regions. The swarms can be so large that weather radar mistakes them for rain clouds. In 2025, it is anticipated to be "one of the largest in recent years," potentially affecting outdoor dining and laundry. Met OfficeYahoo News

Social Media Reactions
Posts like "No outdoor beer today" and "One flew into my mouth..." along with radar images as memes go viral every year. TikTok explanations by news outlets are also popular. TikTokFacebook

Impact on Travel and Measures
・Ensure screens and windows are closed. Avoid wearing white clothes (as they attract ants). Consider indoor alternatives for picnics. InfoMoney

5) Polar Night in Svalbard, Norway: A Journey in "Night" Even During the Day

From mid-November to the end of January, the sun does not rise in Svalbard during the "polar night." Although tourism is limited, it is a unique season for travelers aiming to see the aurora borealis at night (which can sometimes be seen during the day). Considerations for lifestyle rhythm and safety (such as polar bear precautions) are essential. Visit SvalbardOfficial Norway Tourism Site

Social Media Reactions
Posts and Vlogs from travelers about "24 hours of darkness..." draw attention every year, and photos of the "dark blue" and streetlights are popular. Posts from locals provide useful insights on sleep strategies and indoor activities. People.com

Impact on Travel and Measures
・A powerful headlamp and reflective materials are essential. Plan for indoor activities. The best chance to see the aurora is on dark, clear nights. Visit Svalbard

6) Australia's (QLD) "Venomous Jellyfish Season": From November to May, "Suits Are Essential"