Relative Humidity
Definition
The ratio of actual water vapor in the air to the maximum amount it could hold at that temperature. 100% relative humidity means the air is saturated, and fog or clouds will form.
Why Relative Humidity Matters for Pilots
Weather concepts like Relative Humidity appear frequently on both FAA and EASA knowledge exams. More importantly, understanding Relative Humidity 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 Relative Humidity 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
Annual Inspection
Aviation glossary definition and exam tips.
Soft Field Takeoff
Aviation glossary definition and exam tips.
Ipc
Aviation glossary definition and exam tips.
ATPL Theory Complete Guide
Master every subject covered in airline pilot exams.
Free Practice Exam
Test your aviation knowledge with real exam questions.
Built by a commercial pilot
Pass your written for $39 — every track, 60 days
Relative Humidity 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.
Test your knowledge
Think you understand Relative Humidity? Challenge yourself with practice questions covering meteorology and all other exam subjects.
Try Free Practice QuestionsMore Meteorology Terms
METAR(METAR)
Meteorological Terminal Air Report, a standardized format for reporting current ...
TAF(TAF)
Terminal Aerodrome Forecast, a weather forecast specific to an airport covering ...
SIGMET(SIGMET)
Significant Meteorological Information advisory issued for hazardous weather phe...
AIRMET(AIRMET)
Airmen Meteorological Information advisory for weather hazards significant to li...
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 →