Cold Wave in India
- “The India Meteorological Department (IMD) has issued a cold-wave alert for several districts in Telangana, signalling an unusual southward shift of winter severity. This highlights the growing climatic volatility that now exposes even non-traditional regions to extreme temperature stress.”
About Cold Wave
- A cold wave is a sudden and substantial drop in temperature below the normal average for a region during winter.
- IMD Role: The India Meteorological Department (IMD) defines, monitors, and issues colour-coded warnings (Green, Yellow, Orange and Red) for cold waves.
- Declaration Basis: It declares a cold wave using both minimum temperature thresholds and deviations from long-term normal values.
- Baseline: Normal temperature values are determined using climatology data from 1981-2010.
- Core Zone: IMD identified 17 states and UTs as highly prone to severe cold waves from November to March. Telangana is the only South Indian state included in the core cold-wave zone.
Criteria to Declare Cold Waves
- Plains Regions: Declared when either: (a) the minimum temperature is 4°C or lower, or (b) when it is 10°C or lower and 4.5°C-6.4°C below normal.
- Hilly Regions: When the minimum temperature is 0°C or lower and 4.5°-6.4°C below normal.
- Coastal Regions: When the minimum temperature is 15°C or lower and at least 4.5°C below normal.
- Severe Cold Wave: IMD declares a severe cold wave when either: (a) the minimum temperature is 2°C or lower, or (b) it is at least 6.5°C below normal.
Factors for Cold Waves in India
- Western Disturbances: Their eastward movement brings cold, dry north-westerly winds from the Himalayas and Central Asia.
- High-Pressure Systems: The intensification and southward shift of the Siberian High push cold air masses into India.
- Himalayan Snowfall: Heavy snowfall amplifies the advection (horizontal transport) of cold air into the northern plains.
- Cloud Cover: Clear, Cloud-free skies accelerate nighttime heat loss through radiative cooling.
- Dense Fog: Persistent fog blocks incoming solar radiation and intensifies cold-wave conditions.
- La Niña: La Niña events increase the frequency, duration, and severity of cold waves in India.
- Continental Climate: Interior regions experience harsher cold due to the lack of maritime moderation.
Consequences of Cold Waves
- Health Impact: Cold waves increase cases of hypothermia, frostbite, vasoconstriction, asthma, and COPD; India records about 824 annual deaths from cold exposure.
- Agricultural Loss: Frost damages crops during flowering and fruiting stages, while cold stress reduces livestock productivity and overall farm yield.
- Infrastructure Disruption: Thick fog reduces visibility, causing transport delays and accidents. Increased heating demand leads to power outages and electrical system failures.
Way Forward – Cold Wave Management
- Early Warnings: AI-based hyperlocal alerts & IMD district push notifications reduced cold-wave deaths.
- Climate Farming: ICAR frost-tolerant crops and micro-irrigation/polyhouses protect rabi crops from sub-10°C stress.
- Winter Readiness: PMAY thermal-insulated homes & expanded night shelters shield urban poor during 7–10°C spells.
- Transport Safety: Fog-vision systems on highways/trains and smart airport signalling minimise accidents in dense fog.
- Health Response: Winter clinics, mobile camps, and hypothermia awareness drives prevent cold-related morbidity.
“Cold waves are no longer rare events; they are recurring climate alarms.” Strengthening forecasting, public health, and climate-resilient systems is crucial to protecting lives and livelihoods in India’s changing winter conditions.
Reference: The Hindu
PMF IAS Pathfinder for Mains – Question 427
Q. What factors are driving the increasing frequency and severity of cold waves in India? Examine their socio-economic impacts and suggest measures for strengthening cold-wave preparedness and risk management. (250 Words) (15 Marks)
Approach
- Introduction: Write a brief introduction about the cold wave in India.
- Body: Write factors that are driving the increasing frequency and severity of cold waves in India, mention socio-economic impacts and suggest measures.
- Conclusion: Emphasis on an Integrated management strategy to strengthen cold-wave preparedness and risk management.
