Definition
A condition in which the sky above a given level is hidden from view by an airborne layer of clouds, smoke, dust, haze, or other particles, even though the surface visibility may not be restricted. The obscuring layer exists aloft rather than reaching the ground.
Plain English
It means something in the air above you, like a layer of smoke, haze, or dust, is blocking your view of the sky, even though the air down at the surface might still be clear.
Context Anchor
Seen in aviation weather observations and discussions of sky condition, especially when haze, smoke, dust, or ash is present above the airport rather than right at the surface.
Derivation
Obscuration comes from the Latin obscurare, meaning to darken or hide. Aloft is an old English nautical term meaning up high or overhead. Together they describe something hiding the view from above.
Why Pilots Care
Determines whether visual flight is possible at cruise altitudes and influences routing and altitude selection for safety.
Grounding Statement
You may have good visibility near the runway, but a layer of smoke or haze above you can still block your view of the sky and clouds beyond it.
Intuition Check
Do not read “obscuration aloft” as simply “bad visibility.” Here, it specifically means the material blocking the view is above the surface, not based at ground level.
Example Sentence 1
Smoke from distant wildfires created an obscuration aloft, making it difficult to see higher cloud layers during the climb.
Example Sentence 2
Pilots checked the forecast for obscuration aloft before choosing a VFR route over the mountains.