Heatwave grips north and central India; mercury may touch 45°C in Delhi this week

📌 Summary:

• IMD warned of prolonged heatwave to severe heatwave conditions across northwest and central India for 7 days (till May 24)
• States under heatwave watch: Delhi, UP, Punjab, Haryana, MP, Vidarbha; Telangana May 19–21; Bihar/Marathwada May 18–19
• Severe heatwave warning for West UP (May 19–24) and East UP (May 19–20)
• Warm-night conditions over parts of West UP on May 18-19 (compounds health risk by limiting overnight cooling)
• Delhi: max temperature 43–45°C till May 21; heatwave at isolated places May 19, 20, 21; surface winds 20–30 kmph, gusts up to 40 kmph
• Highest temperature in country recorded at Banda, UP — 46.4°C
• Temperature departures markedly above normal by 5.1–6°C over West/East MP and Gujarat
• IMD advises: avoid heat exposure, stay hydrated, use ORS, buttermilk, lemon water; particular risk to infants, elderly, those with chronic diseases

🎯 UPSC Relevance: GS1 (Climatology, Geophysical phenomena) and GS3 (Disaster Management); heatwaves are notified as State-specific disasters in many states and trigger NDMA Heat Action Plan obligations

📝 Prelims Facts:

• IMD heatwave criteria (plains): max temp ≥40°C AND departure ≥4.5°C from normal; "severe" if departure ≥6.5°C
• Hot day & warm night: when both day and night temps are above normal
• IMD = India Meteorological Department, under Ministry of Earth Sciences (MoES)
• Banda (UP) — 46.4°C highest in country this cycle
• NDMA's National Guidelines on Heat Wave (2019) — Heat Action Plans now in 23+ states/UTs

🔑 Key Term: Heatwave — IMD defines a heatwave in the plains when maximum temperature reaches ≥40°C and the departure from normal is ≥4.5°C; "severe heatwave" if the departure is ≥6.5°C, or actual maximum touches ≥45°C (irrespective of departure).