According to Köppen classification, what type of climate does Arunachal…

Concept: The Köppen climate classification groups world climates into five broad types by dominant temperature and moisture regime — A (tropical), B (dry/arid), C (warm temperate), D (cold/continental), and E (polar) — and further qualifies each with a second letter for the seasonal rainfall pattern (for example w = dry winter, f = no dry season) and a third letter for summer/winter temperature severity (for example a/b/c for summer warmth, or g for the special "Ganges type" premonsoon heat curve used in Indian textbooks).

Application: Arunachal Pradesh's high-altitude tracts lie in the Eastern Himalayan belt, where the standard Indian-textbook regional classification assigns the D (cold/continental) group: winters stay cold and humid rather than dry — so f applies (no marked dry season, unlike w) — and summers are short and cool, with at least one month averaging above 10°C (ruling out the polar ET type, which has no month that warm) but fewer than four months doing so (giving the cooler "c" subtype rather than a warmer "a"/"b"). This combination is coded Dfc, so "Dfc – Cold humid winter with short summer" is the type conventionally assigned to Arunachal Pradesh in this classification scheme.

Cross-check — why the other codes do not fit Arunachal Pradesh's terrain:

• Cwg (monsoon with dry winter) marks the Ganges-type warm-temperate climate of the Indo-Gangetic plain (Punjab to Bihar/West Bengal), where winters are markedly dry and pre-monsoon months turn very hot — a lowland-plain profile, not a high-Himalayan one.

• Amw (monsoon with short dry season) marks India's tropical monsoon coastal belt (the Konkan–Malabar coast), where rainfall stays heavy for most of the year at low elevation with only a brief drier spell — again a lowland/coastal profile.

• BShw (semi-arid steppe) marks the dry, low-and-erratic-rainfall tracts of interior/western India, the climatic opposite of Arunachal Pradesh's high, humid conditions.

Hence, only the D-group cold-humid classification fits Arunachal Pradesh's Himalayan altitude and year-round rainfall pattern, confirming Dfc – Cold humid winter with short summer as the answer.