April 2026
In short: India's places in the news and physical geography this month — distilled for SI/Constable Prelims.
Current Affairs — India › Geography · 12 min read · Free to read · English & Telugu
Bilingual study notes for the Andhra Pradesh Police SI & Constable exams (SLPRB AP) by AP Police Hub, a product of Anvil Academy.
April 2026's physical geography — IMD's first below-normal monsoon forecast in 11 years, the day all 50 of the world's hottest cities were in India, and two new Cabinet-cleared hydropower projects on the Lohit and Kamala rivers of the Brahmaputra system.
April 2026 — At a Glance
April 2026's genuinely fresh Geography content was climatological and hydrological rather than the usual 'places in the news' atlas — fully carried this month in the Science digest. The India Meteorological Department issued its first-stage Long Range Forecast for the 2026 southwest monsoon on 13 April, predicting below-normal rainfall for the first time in 11 years, against a backdrop of weakening La Niña and an approaching El Niño. Weeks earlier, on 27 April, an extraordinary heat event put every one of the world's 50 hottest-ranked cities inside India, driven by a heat trough over Rajasthan and the retreat of cooling westerlies. And on the infrastructure side, the Union Cabinet cleared two large hydropower projects on the Lohit and Kamala rivers in Arunachal Pradesh — both part of the wider Brahmaputra river system that dominates India's northeastern physical geography.
1. IMD's 2026 Monsoon Forecast — First Below-Normal Call in 11 Years
The forecast
- What — The India Meteorological Department (IMD), Ministry of Earth Sciences, issued its first-stage Long Range Forecast for the 2026 southwest monsoon season (June-September) on 13 April 2026 — the seasonal rainfall over the country as a whole is most likely to be below normal, quantitatively 92% of the Long Period Average (LPA), with a model error of ±5%.
- The LPA benchmark — The Long Period Average (LPA) of the seasonal rainfall over the country as a whole, based on 1971-2020, is 87 cm; the forecast 90-95% of LPA range is IMD's official 'below normal' category.
- Probability breakdown — Of the five official categories, IMD gave 'Deficient' (<90% LPA) a 35% probability and 'Below Normal' (90-95%) a 31% probability — both well above their climatological averages (16% and 17% respectively); 'Above Normal' and 'Excess' were given only 6% and 1% probability.
IMD's five-category probability forecast, 2026 SW monsoon| Category | Rainfall range (% of LPA) | Forecast probability |
|---|
| Deficient | < 90% | 35% |
| Below Normal | 90-95% | 31% |
| Normal | 96-104% | 27% |
| Above Normal | 105-110% | 6% |
| Excess | > 110% | 1% |
Why — the climate drivers
- Pacific Ocean (ENSO) — Weak La Niña-like conditions are transitioning to ENSO-neutral over the equatorial Pacific; IMD's own Monsoon Mission Climate Forecast System (MMCFS) suggests El Niño conditions may develop during the monsoon season itself — El Niño years typically bring weaker monsoons to India.
- Indian Ocean Dipole (IOD) — Neutral IOD conditions currently prevail; climate models indicate positive IOD conditions likely to develop towards the end of the monsoon season — a positive IOD can partly offset an El Niño's dampening effect on rainfall.
- Northern Hemisphere snow cover — January-March 2026 snow cover over the Northern Hemisphere/Eurasia was slightly below normal — this matters because winter/spring snow cover has a general inverse relationship with the subsequent monsoon's rainfall.
- Forecasting protocol — IMD has issued LRF in two stages since 2003 (first in April, updated end-May); since 2021 it uses both dynamical (Multi-Model Ensemble/MME) and statistical forecasting; the updated forecast is due last week of May 2026.
2. Physical Geography Special — The Day India Held All 50 of the World's Hottest Cities
The event
- What — On 27 April 2026, air-quality/heat-index data compiled by AQI.in showed every single one of the world's top 50 ranked hottest cities was located inside India — displacing the traditional hottest zones of the Middle East, Africa and Australia entirely from that day's list.
- The numbers — Banda, Uttar Pradesh recorded the day's highest single-city peak at 46.2°C; Noida, New Delhi, Faridabad, Gurgaon, Greater Noida and Ghaziabad all clustered between 44.1-44.9°C; Delhi's base station (Safdarjung) logged a maximum of 42.8°C, 5.1°C above normal, never dropping below 33.7°C overnight.
Why it happened
- The weather system — Caused by pre-monsoon seasonal heating, intensified by a heat trough driven by a low-pressure system over Rajasthan; the westerly winds that normally keep winter cool had retreated, letting a hot continental air mass from the northwest press down over the plains.
- Broader IMD outlook for April-June 2026 — IMD's own seasonal outlook (issued 1 April 2026) had flagged above-normal night-time temperatures for most of the country, and above-normal heatwave days over coastal Odisha, West Bengal, Tamil Nadu, Puducherry and Andhra Pradesh plus isolated parts of Gujarat, Maharashtra and Karnataka — with potential crop damage (poor grain-setting, flower drop) in rice, maize and pulses across eastern and southern India.
3. New Hydropower on the Brahmaputra System — Kalai-II & Kamala Projects
This month's live Economy digest names these approvals only in a single generic quick-fact line, without identifying the rivers or project details. The river-system geography behind them is presented here in full.
The two new projects
- What — The Cabinet Committee on Economic Affairs (CCEA), chaired by the PM, approved investment for two hydroelectric projects in Arunachal Pradesh — the Kalai-II HEP and the Kamala HEP — in early April 2026.
- Kalai-II HEP — 1,200 MW (6×190 MW + 1×60 MW) on the Lohit River in Anjaw district — India's easternmost district; outlay ₹14,105.83 crore; completion timeline 78 months.
- Kamala HEP — 1,720 MW (8×210 MW + 1×40 MW), a storage-based scheme with a 216-metre concrete gravity dam and underground powerhouse, on the Kamala River across Kamle, Kra Daadi and Kurung Kumey districts; outlay ₹26,069.50 crore; implemented via an NHPC-Arunachal Pradesh government joint venture.
The rivers — placing them in the Brahmaputra system
- The Lohit — The Lohit is one of the three principal headwater rivers of the Brahmaputra (with the Siang/Dihang and Dibang), rising beyond the eastern Himalaya and joining the Siang near Sadiya, Assam to form the Brahmaputra proper.
- The Kamala — The Kamala is a tributary of the Subansiri, which is itself a major tributary of the Brahmaputra — so the Kamala HEP sits two levels up the tributary hierarchy from the Brahmaputra's main channel; the earlier-known Subansiri Lower HEP (India's largest hydropower project, ~2,000 MW) is downstream on the Subansiri's main course.
- Strategic co-benefits — Both projects are framed as supporting peak demand management, national grid balancing and flood moderation in the Brahmaputra basin, alongside other Arunachal projects under development — Subansiri Lower, Dibang Multipurpose (2,880 MW) and Etalin (3,097 MW) — positioning the state as a key hub in India's renewable-energy and border-infrastructure strategy.