Cloud Ceilings: What Pilots Should Know (Complete Guide)
For new student pilots, weather reports can be tricky to understand. They use terms that we don't often hear in our everyday lives. One of those terms is "cloud ceilings". This may seem like a strange phrase, but it's actually very important for new pilots to know if they want to read weather reports (METARs) correctly.
In this article, we'll break down what cloud ceilings are and help you understand them better.
For new student pilots, weather reports can be tricky to understand. They use terms we don’t often hear in everyday life. One of those terms is “cloud ceiling.” It may sound odd at first, but it’s extremely important if you want to read METARs and TAFs correctly and make safe go/no-go decisions.
In this article, we’ll break down what cloud ceilings are, how they’re measured, and how to interpret ceilings in common aviation weather products.
Let’s get started!
What Are Cloud Ceilings?
A cloud ceiling is the altitude of the lowest cloud layer that covers more than half the sky. In aviation weather, this typically means the first layer reported as broken (BKN) or overcast (OVC).
Cloud ceilings are reported as a height above ground level (AGL). For example, a ceiling of 800 feet AGL means the lowest broken/overcast layer is 800 feet above the airport’s surface.
How Cloud Ceilings Are Measured
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Ceiling balloons: Special helium balloons used to estimate cloud height.
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Laser ceilometers: A ceilometer sends light upward and measures return time to calculate cloud base height.
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Pilot reports (PIREPs): Pilots provide real-world cloud base/top reports that add valuable context.
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Human observers: Weather observers can estimate cloud layers visually (helpful, but generally less precise).
Known Terrain and Structure Heights
Another practical way pilots “sanity check” ceilings is by comparing clouds to terrain or structures with known heights (towers, ridgelines, mountain passes). This is especially important around mountains, where cloud coverage can quickly turn into reduced visibility and dangerous VFR conditions.
Cloud Ceilings vs. Cloud Base
Cloud bases and ceilings are related, but they are not the same thing.
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Cloud base is the height of the lowest visible part of a cloud layer.
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Ceiling is the height of the lowest layer reported as BKN or OVC (more than half the sky covered), typically below 20,000 feet.
The sky can have multiple cloud layers, and METARs describe them using coverage amounts:
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FEW = 1/8 to 2/8 coverage
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SCT = 3/8 to 4/8 coverage
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BKN = 5/8 to 7/8 coverage (this can form a ceiling)
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OVC = 8/8 coverage (this is a ceiling)
Ceilings matter because they directly affect VFR operations. For example, a ceiling near pattern altitude can create serious constraints for departure, arrival, and maneuvering.
Cloud Ceiling According to the METAR
Before planning a flight, pilots use METARs to see current conditions at departure and destination airports. If ceilings are low (or trending downward), you may need to adjust your route, delay the flight, or cancel entirely—especially if you’re VFR-only.
For the most up-to-date official weather, use aviationweather.gov.
How to Read Cloud Coverage on a METAR
Example METAR (Houston):
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KIAH 152333Z 27008KT 3SM RA BR FEW006 BKN013 OVC025 18/17 A3013 RMK AO2 P0002 T01780167
Decoded cloud information:
Ceiling: 1,300 feet AGL (because BKN013 is the lowest BKN/OVC layer)
Layers: FEW at 600 ft AGL, BKN at 1,300 ft AGL, OVC at 2,500 ft AGL
How to Read Cloud Coverage on a TAF
Example TAF (Houston):
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KIAH 152323Z 1600/1706 11008KT P6SM VCSH OVC015
FM160600 34006KT 4SM SHRA BR OVC007
FM161000 35007KT 6SM BR VCSH BKN009 BKN015
FM161200 34007KT P6SM BKN015
FM161400 34010G18KT P6SM FEW250
FM170000 34008KT P6SM SKC
Decoded highlights (cloud-focused):
OVC015 = ceiling 1,500 ft AGL in the initial period
FM160600 OVC007 = ceiling drops to 700 ft AGL
FM161000 BKN009 BKN015 = ceiling 900 ft AGL (lowest BKN)
FM161400 FEW250 = no ceiling reported (FEW does not count as a ceiling)
FM170000 SKC = clear skies
For more on METARs
If you want to go deeper, check out: How to Read METAR Aviation Reports.
Frequently Asked Questions
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What counts as a “ceiling” in a METAR?
The lowest cloud layer reported as BKN or OVC. FEW and SCT layers do not create a ceiling.
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Is a cloud base the same as a ceiling?
No. A cloud base is the height of the lowest part of a layer. A ceiling is the lowest layer that covers more than half the sky (BKN/OVC).
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How do I find the ceiling quickly in a METAR?
Look for the lowest BKN or OVC group and read the height (e.g., BKN013 = 1,300 ft AGL).
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What does “no ceiling” mean?
If the METAR only shows FEW or SCT layers (or SKC/CLR), there isn’t a ceiling reported because coverage is not greater than half the sky.
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Why do ceilings matter so much for VFR pilots?
Ceilings can limit safe maneuvering altitude, pattern operations, and route options—especially if conditions trend toward marginal VFR or IMC.
Takeaway
Safe pilots don’t just fly well—they plan well. Understanding cloud ceilings gives you quick insight into whether conditions are truly VFR, trending marginal, or likely to require an IFR-capable plan.
Keep learning, keep cross-checking weather sources, and always prioritize safety over convenience.
Fly safe!
Want to learn more about aviation weather?
These guides can help you sharpen your weather knowledge:
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12 Types of Clouds Pilots Must Recognize [#12 Can be Deadly]
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7 Types of Turbulence Every Pilot Should Know (What Causes It)
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