The Secret Behind London’s Fog and What It Means for Your Luggage

Thu, 16 Apr 2026 00:05:37 +0000

The Secret Behind London’s Fog: Why London’s Mist Matters for Your Luggage and Travel Plans London’s fog—locally known as “pea-souper” due to its thick, dense nature—has inspired stories, films, and centuries of fascination. More than just a quirky weather phenomenon, London’s iconic mist carries both charm and challenges, especially for travelers navigating the city’s iconic streets with their luggage. But what truly lies behind London’s fog? And why should you care if you’re bulk-tagging your suitcase before stepping off the Tube? ### The Science Behind London’s Fog London’s fog is primarily caused by a mix of geography, weather patterns, and urban activity. The city’s River Thames and surrounding green spaces create humidity-friendly conditions, while older urban infrastructure traps pollutants and moisture in the air. Combined with cold temperatures—especially in autumn and winter—these elements spark the formation of dense ground fog known officially as street fog. Unlike dense smoke, street fog consists of water droplets suspended in air, creating the moment-by-moment “pea-souper” visibility that shocks first-time visitors.