Expert Explains | What makes this summer particularly intense for India, and how better data collection can help

📌 Summary:

• The India Meteorological Department (IMD) has warned of prolonged to severe heatwave conditions over northwest and central India; an expert explains why this summer is unusually intense and how data can aid mitigation

• The heat is partly a normal seasonal phenomenon — April-May naturally brings extreme heating from high solar radiation, dry continental winds, low soil moisture and seasonal low-pressure heat zones over Rajasthan and adjoining Pakistan

• What is abnormal this year is the intensity, persistence and large spatial extent — abnormally high temperatures over prolonged periods with limited nighttime cooling, indicating severe heatwave conditions

• Amplifying factors: reduced pre-monsoon rainfall, persistent dry air circulation, extensive land-surface warming, and the Urban Heat Island effect driven by unplanned urbanisation and construction; climate change acts as a "background stress multiplier" raising baseline temperatures and making heatwaves more frequent, longer and severer

• Global drivers: El Niño conditions are developing in the equatorial Pacific (onset projected May-July), suppressing moisture and intensifying pre-monsoon heat build-up — the IMD has projected the 2026 southwest monsoon at 92% of the long-period average (below normal), with El Niño a primary driver; long-term anthropogenic warming is the second global factor

• On data: temperature maps differ by method — station-based interpolation (accuracy depends on network density), satellite remote sensing of surface "skin" temperature (e.g. MODIS, Landsat), and numerical weather model simulations (ECMWF, GFS) which alone offer 4-15 day predictive capability; the IMD runs an India-adapted GFS and ingests ECMWF data for heatwave guidance

🎯 UPSC Relevance: GS3 — heatwave as a disaster, climate-change-driven extreme weather, El Niño and the monsoon, the Urban Heat Island effect, and the role of data and early-warning systems in disaster mitigation.

📝 Prelims Facts:

• El Niño is a warming of sea-surface temperatures in the eastern equatorial Pacific, generally associated with a weaker Indian southwest monsoon

• The IMD has projected the 2026 southwest monsoon at 92% of the long-period average (below normal)

• MODIS and Landsat are satellite thermal sensors; ECMWF and GFS are global numerical weather prediction models

🔑 Key Term: Urban Heat Island (UHI) — the phenomenon whereby cities are significantly warmer than surrounding rural areas because concrete, asphalt and reduced vegetation absorb and retain heat, intensified by unplanned urbanisation.