36 questions on this topic, recalled by candidates after DGCA sittings between 2021 and 2026. Together they were asked 113 times; the most repeated come first. Pick a year to see only what was asked that year.
C. CB
Showers are short, heavy bursts from convective cloud - cumulonimbus (and large cumulus). NS gives continuous rain; AC gives little or none.
B. Stratus
Drizzle is fine droplets from a shallow, low layer cloud - stratus (or thin stratocumulus). The cloud is too shallow for drops to grow big.
C. Cumulonimbus
Only the cumulonimbus has the updraughts to grow hail. It is also the cloud of heavy showers, lightning, severe icing and turbulence.
B. Afternoon
Surface heating builds through the day, so convection and showers over land peak in the afternoon.
B. Nimbostratus
Nimbostratus is the thick, dark, ragged-based rain cloud of the warm front, giving continuous moderate or heavy rain for hours.
A. Cirrus
Cirrus is a thin, high cloud of ice crystals; anything that falls from it evaporates long before reaching the ground.
B. AC and AS
The "alto" clouds - altocumulus and altostratus - are the medium clouds. CI, CC and CS are high; CU and CB are clouds of vertical development.
B. Virga
Virga are the trails of rain or snow that evaporate in dry air before reaching the ground. They can still mean downdraughts below the cloud.
A. Afternoon
Over flat land the trigger is surface heating, which peaks in the afternoon. (Over the sea and in valleys, night and early-morning storms are more common.)
B. A medium cloud of sheet type
"Alto" means medium level; "stratus" means sheet or layer. AS is a grey medium-level sheet through which the sun appears as if through ground glass.
C. Having strong vertical development
Hailstones grow as strong updraughts carry them up and down through supercooled water again and again. That needs a deep cloud with violent vertical currents - the CB.
C. Stratiform cloud
Stable air lifted over high ground cools to saturation but does not rise on its own, so it spreads out as layer (stratiform) cloud and hill fog on the windward side. Unstable air lifted the same way would build CU or CB.
B. Summer
Tropical rain is mostly convective, fed by strong heating and moist air - so it peaks in the summer (in India, the SW monsoon months).
B. Cold clouds
A cloud reaching above the 0 °C level contains ice crystals and supercooled water, and makes rain by the ice-crystal process - a cold cloud. One entirely below freezing level is a warm cloud.
A. Warm clouds
In warm clouds (no ice) raindrops grow by bigger droplets colliding with and absorbing smaller ones - coalescence. In cold clouds the ice-crystal (Bergeron) process does the work.
B. Thunderstorm (CB)
Those are the ingredients of a thunderstorm: a steep lapse rate, plenty of moisture, and surface heating as the trigger.
A. Mintra level
Contrails form only in a band of cold air: below the MINTRA level (minimum trail level) it is too warm; above the MAXTRA level they no longer form.
B. At night and in the early morning
At night the land breeze blowing out to sea converges with the sea air offshore, lifting it and setting off showers - so coastal areas often get their rain at night and in the early morning.
A. Winter
Temperate rain comes mostly from frontal depressions, which are most frequent and vigorous in winter.
A. Winter
Western disturbances - frontal systems from the Mediterranean - bring rain and snow to J&K and the western Himalayas mainly in winter.
A. Turbulence below the cloud base and smooth air above the cloud tops
Fair-weather cumulus sits on top of thermals. Below the base the rising and sinking air makes it bumpy; above the tops the air is usually smooth. That is why pilots climb above a cumulus layer.
B. Cloud Burst
A cloudburst is an extreme shower - a very large amount of rain in a very short time, usually from a vigorous CB over hilly terrain. Flash floods are what often follows it.
A. Rain-bearing
Nimbus means rain cloud: nimbostratus is the layered rain cloud, cumulonimbus the heaped (shower and thunder) one.
B. Continuous (steady) rain or snow
Layer clouds come from gentle, widespread lifting, so their precipitation is steady and continuous. Showers and hail belong to convective clouds.
B. Capillatus
CB capillatus has a fibrous, glaciated top spreading into an anvil. Castellanus describes turreted AC or CC; uncinus is hooked cirrus.
C. Strong convective updraughts
A CB is the end product of deep convection: strong updraughts in unstable, moist air. Fronts and hills can trigger it, but the updraught is what builds it.
C. Cumulonimbus
Strong updraughts in heaped (cumuliform) cloud mean vigorous convection - the development that ends in cumulonimbus.
B. Convective activity
In the tropics fronts are rare and heating is strong, so most rain comes from convection - showers and thunderstorms.
B. Leeward side of the mountains
Moist air drops its rain as it rises up the windward slope; descending the lee side it warms and dries, leaving a rain shadow - e.g. east of the Western Ghats.
C. 2.5
In India a "rainy day" is one with 2.5 mm or more of rain in 24 hours.
A. Subsidence
Descending air is compressed and warms adiabatically, so its relative humidity falls and the cloud droplets evaporate. Convection and orographic lifting do the opposite - they cool the air and build cloud.
A. 4000 ft
The temperature and the dew point close on each other at 3 - 0.3 = 2.7 °C per 1000 ft. The 10 °C spread therefore closes after about 10 ÷ 2.7 = 3.7, or roughly 3,700 ft - nearest to 4000 ft. That level is the lifting condensation level, which is the cloud base.
A. Has a lower base and gives continuous rain or snow
Nimbostratus is the dark grey rain cloud - thick enough to blot out the sun, extending through the medium and low levels, giving continuous rain or snow. Altostratus is the thinner, lighter grey sheet above it, through which the sun shows as if through ground glass.
A. Nimbostratus
Nimbostratus is the deep, layered rain-and-snow cloud - thick enough and cold enough through its depth for ice crystals to grow to a size that reaches the ground. Stratus is too thin and gives only drizzle, and cirrus is far too high, its crystals evaporating long before they arrive.
B. Subsidence and warming of the air
Cloud is water that has condensed because the air was cooled to saturation. Reverse that and the cloud evaporates: sinking air is compressed and warms, so its relative humidity falls and the droplets return to vapour. This is why subsiding air in a high gives clear skies.
A. Ci, Cs and Cc
The correct answer is: Ci, Cs and Cc.
These are candidates' recollections, not official DGCA papers: wording can differ from the paper as set. Every answer was checked against the DGCA CARs, AIP India, ICAO documents or worked calculation (independent check completed 17 Oct 2026). Spotted a mistake? Tell us and we will check it against the source.