Skip to main content
Meteorology

Fog

Definition

A cloud at ground level that reduces visibility below 1 kilometer. Types include radiation fog (nighttime cooling), advection fog (warm air over cold surface), and upslope fog. A major cause of IFR conditions.

Why Fog Matters for Pilots

Weather concepts like Fog appear frequently on both FAA and EASA knowledge exams. More importantly, understanding Fog helps pilots make sound go/no-go decisions and avoid hazardous conditions in flight. Weather-related accidents remain a leading cause of general aviation incidents.

💡

Exam Tip

This concept is commonly tested in meteorology-related questions on FAA and EASA exams. Make sure you can explain Fog in your own words for the oral exam. Practice applying this concept to real-world scenarios, not just memorizing the definition.

Related Terms

Share this with a fellow pilot

Related Content

Built by a commercial pilot

Pass your written for $39 — every track, 60 days

Fog is one of 5,500+ exam topics in the All-5 Bundle: PPL / IR / CPL / ATPL / Part 107 / TAE. One-time payment, no subscription. Free 30-day extension if you fail your real exam.

Get the $39 Bundle →

Test your knowledge

Think you understand Fog? Challenge yourself with practice questions covering meteorology and all other exam subjects.

Try Free Practice Questions

Or get the $39 All-5 Bundle (60 days)

More Meteorology Terms

Would you pass the real exam right now?

Take a free practice quiz — real FAA-style questions, instant score. No signup to start.

Take the free quiz →