According to Köppen’s Climatic Classification, the Amw climate is found predominantly in which part of India?
- (a)North-western India
- (b)Western coastal region
- (c)Thar Desert
- (d)Northern plain
Correct — B, Western coastal region.
Read the code in pieces rather than as one label.
The capital A puts the station in the tropical group, where even the coldest month averages 18°C or more. The m marks a monsoon regime: a short dry season repaid by very heavy rain. The trailing w says that dry season arrives in winter.
Of the four regions offered, the one that satisfies all three conditions together is the coastal strip lying under the windward face of the Western Ghats, south of Goa. It takes the full force of the south-west monsoon and stays hot through January, so the Western coastal region is keyed.
The idea to carry away: in a Köppen code the first letter fixes the temperature group and the letters after it fix the rain — how much dry season there is, and when it falls.
- (a)North-western India — This quarter of the country sits on the dry end of India's rainfall gradient, so the m in Amw — which requires a heavy, monsoon-fed rainfall total — cannot be satisfied there.
The codes mapped over it come from Köppen's dry B group, chiefly BShw, the semi-arid steppe type, which is placed over north-western Gujarat and parts of western Rajasthan and Punjab; the plainward stretches to its east carry Cwg instead.
- (c)Thar Desert — The desert fails the rainfall test outright. Amw describes a place drenched for months with only a brief break; the Thar has a rainfall deficit for most of the year, which is a B-group condition, not an A-group one.
Extreme western Rajasthan is the home of BWhw, the hot desert type. The w in Amw only says when the dry spell falls; it is not a marker of aridity.
- (d)Northern plain — The northern plain fails the temperature test rather than the rainfall one. Its January means drop below the 18°C floor that the A group demands, so it leaves the tropical group altogether and moves into C.
The plain is the standard home of Cwg, the monsoon type with a dry winter, mapped across the Ganga plain and adjoining tracts of north India.
Köppen's classification is empirical: it sorts climates by measured temperature and precipitation values rather than by causes, and compresses each type into a short letter code.
The first, capital letter names one of the five broad groups — A tropical, B dry, C warm temperate, D cold temperate, E polar. The letters that follow describe the precipitation regime, and in the Indian adaptation a further letter records the season in which the dry period falls.
So Amw unpacks as tropical (A), monsoon with a short dry season (m), dry season in winter (w).
The letter codes and the belts they name are standard in Indian school geography, and the same code-to-region table recurs across commission papers (see the linked HPSC 2021 and CDS 2022 items).
Its value is that it forces two tests at once. A region qualifies only if its temperatures and its rainfall pattern both fit, which is why belts that look alike on a rainfall map — the two monsoon coasts, for instance — end up with different codes.
- In Köppen's scheme the letter A marks tropical climates, where the mean temperature of the coldest month is 18°C or above.
- The lower-case m stands for monsoon: a short dry season offset by very heavy rainfall in the wet months.
- In the Indian adaptation the trailing w records that the dry season falls in winter, not that the climate itself is dry.
- Amw, tropical monsoon with a short dry winter, is mapped onto the west coast of India south of Goa.
- Extreme western Rajasthan is mapped as BWhw, the hot desert type; the semi-arid steppe belt beside it is BShw.
- Cwg, monsoon with a dry winter, is mapped over the Ganga plain, eastern Rajasthan, northern Madhya Pradesh and most of North-East India.
- The Coromandel coast of Tamil Nadu is mapped as As, the monsoon type whose dry season falls in summer.
- Arunachal Pradesh is mapped as Dfc, cold humid winter with a short summer.
A code names a temperature group and a rain regime at once, so a belt fits only when both tests pass.
- Reading only the A and treating Amw as 'anywhere tropical in India' — the m and w narrow it to a heavily rained monsoon belt with a brief winter break.
- Taking the w as a sign of dryness and jumping to the Thar; w names the season of the dry spell, while the desert code is BWhw.
- Assuming any coast will do. India has two monsoon coasts and they carry different codes — the western one Amw, the Coromandel one As.
- Forgetting the 18°C floor on the coldest month, which is precisely what pushes the Ganga plain out of A and into Cwg.
- Blurring Am and Amw, or reciting a code without its region — the mark here depends on holding the code and the belt together.
The same code table is worked in both directions: a code is given and the belt has to be named, or a belt is described and the code has to be picked.
It also appears as a four-pair matching set, and as a statement set in which one code-to-region pairing has been planted wrong.
The region is sometimes described in words while the codes sit in the options — the western fringe of Rajasthan (CDS 2022), the driest part of Rajasthan (HPSC 2021) — so the belt has to be recognised before the code can be matched.
HPSC_2021_PRE_GSII_Q62021The same code-to-region table, including Amw and the western coast of India south of Goa. What differs is the format: it is a four-pair matching set that also carries BWhw, Dfc and As, so one wrong pairing sinks the whole answer, whereas the UKPSC item isolates a single code.
CDS_GK_2022_I_Q322022Draws on the same Köppen mapping of India but from the dry end — it asks for the type fitting the western fringe of Rajasthan, and offers Amw as one of the choices. It therefore tests the very confusion the UKPSC options set up between the monsoon coast and the arid north-west.
CDS_GK_2024_I_Q862024Tests the letter grammar alone — what BW stands for — with no Indian region attached. It is the layer beneath the UKPSC item: decode the letters first, then locate them on the map, which is the step the UKPSC question actually marks.
UKPSC_2016_PRE_PaperI_Q282016The same commission on the same scheme, with Amw among its options. It runs the other way, naming a region — North-East India including North Bengal — and asking which description fits, and it pairs each code with a verbal gloss rather than leaving the letters bare.
RPSC_2021_PRE_Prelims2021_Q612021Also a Köppen code-to-place exercise, but pitched at district level inside one state rather than at national belts. Its Bwhw and Bshw pairs turn on the same desert-versus-steppe distinction that separates the UKPSC item's north-western and Thar options from the keyed answer.
- practice — not a real PYQ
In the Köppen scheme as mapped for India, which code describes the west coast of India south of Goa?
- (a)As
- (b)Aw
- (c)Amw
- (d)Cwg
Answerc — Amw is the tropical monsoon type with a short dry winter, and it is the code placed over the west coast south of Goa.As is mapped onto the Coromandel coast, where the dry season falls in summer. Aw, tropical savanna, covers much of the peninsular plateau south of the Tropic of Cancer. Cwg belongs to the Ganga plain, whose winters are too cool for the A group.
- practice — not a real PYQ
In the code Amw as applied to Indian climatic regions, the letter 'w' indicates that
- (a)the region is arid through the year
- (b)the dry season falls in winter
- (c)the coldest month averages below 18°C
- (d)rainfall is spread evenly across the year
Answerb — the trailing w records the timing of the dry season, placing it in the winter months.Option a confuses a season marker with an aridity marker; year-round dryness would put the station in the B group. Option c states the opposite of what the A in Amw requires. Option d would rule out a dry season altogether, which is what the f letter signifies.
- practice — not a real PYQ
Under Köppen's classification as mapped for India, extreme western Rajasthan is placed in which type?
- (a)BShw
- (b)BWhw
- (c)Amw
- (d)Cwg
Answerb — BWhw, the hot desert type, is the code mapped over extreme western Rajasthan.BShw, the semi-arid steppe type, rings the desert core — over north-western Gujarat, the rest of western Rajasthan and parts of Punjab — so it describes the drier margin rather than the desert itself. Amw needs the heavy monsoon rainfall the region lacks, and Cwg is the Ganga plain's code.
- practice — not a real PYQ
The Köppen type As, as mapped in India, is associated with which coast?
- (a)Konkan coast
- (b)Malabar coast
- (c)Coromandel coast
- (d)Kathiawar coast
Answerc — As, the monsoon type with a dry summer, is mapped onto the Coromandel coast of Tamil Nadu, which draws much of its rain in the retreating-monsoon months.The Malabar coast is Amw territory, and the Konkan strip lies on the same western, south-west-monsoon-fed side of the peninsula. Kathiawar, in Saurashtra, sits in the drier north-west rather than in a dry-summer monsoon belt.