IMD Predicts a Colder and Longer Winter for North and Central India

IMD Predicts a Colder and Longer Winter for North and Central India

Why in News?

The India Meteorological Department (IMD) has forecasted a colder and longer winter across North and Central India. These regions may witness below-normal temperatures and increased cold wave days, indicating a significantly harsher winter season ahead.

Highlights of IMD’s Winter Forecast

• The India Meteorological Department (IMD) predicts a colder-than-normal winter for many parts of central and northern India. The IMD issues this outlook for the period December 2025 to February 2026 and expects minimum temperatures to be normal to below normal in the affected zones.
• The IMD identifies central India and adjoining northwest India as the main regions likely to feel the chill. States named include Madhya Pradesh, Uttar Pradesh, Rajasthan, Haryana, Punjab, Delhi, Gujarat, and parts of Maharashtra. The IMD also notes that some peninsular pockets such as Telangana may record below-normal minima. 
• The IMD expects a higher number of cold wave days than typical winters in the highlighted regions and estimates about four to five extra cold wave days in many districts compared to a usual winter. The IMD links this as an increase in frequency rather than a uniform rise in intensity.
• The IMD states that polar vortex modulation and ongoing La Niña factors can push colder air masses toward the Indian subcontinent. The IMD connects these drivers to observed temperature anomalies in November 2025.
• The IMD issues short-term cold wave warnings for isolated pockets in the plains and foothills and warns of isolated cold wave conditions in districts of Punjab, Haryana, Delhi and parts of Madhya Pradesh. The IMD also flags dense fog risks in early winter mornings in northern plains.

What is a “Cold Wave”?

• A cold wave refers to an unusual and sharp drop in air temperature near the surface that makes the weather seriously chilly. The responsible official agency India Meteorological Department (IMD) defines it using clear temperature-based thresholds. 
• For plains, a cold wave is flagged when the minimum temperature at a weather station falls to 10 °C or less and/or the temperature deviates 4.5 °C to 6.4 °C below normal. In more severe cases it is considered when minima drops to 4 °C or less.
• For hilly regions, a cold wave may be declared when the minimum temperature reaches 0 °C or less, along with a departure below normal. The agency sometimes also warns about a “Severe Cold Wave” (SCW) if the temperature dips much more below normal, or hits the lower threshold.
• Cold wave conditions often coincide with other weather stresses: sharp air pressure rise, clear skies (leading to high night cooling), wind chill (when wind speed increases), frost or icing risk, and dense fog or low visibility during winters.
• Cold waves in India mostly strike during winter months, roughly November to March, with December and January being the peak months. 
• Regions most prone to cold waves are collectively termed the “Core Cold-Wave Zone (CCZ)”. This includes large areas of north, northwest, central, east and northeast India.
• Cold waves tend to strike when cold air masses from higher latitudes often from north or northwest move southwards, sometimes aided by larger scale atmospheric patterns or pressure ridges. 

Cold Wave Patterns, Trends & Frequency

• A major study covering the period 1971–2010 analysed cold wave and severe cold wave events over 86 stations across India. The study found that the highest number of cold wave events occurred in January across what is called the Core Cold-Wave Zone.
• That same study noted that during years of La Niña cold waves tend to become more frequent and widespread. Conversely, during El Niño years (warmer Pacific waters), cold wave frequency and spatial extent tend to reduce. These patterns suggest a clear link between large-scale global climate phenomena and cold wave risks in India.
• A recent study covering 1951–2022 showed that in the last decade, many parts of central and eastern India have recorded significantly more cold wave days per decade. Some districts now show an increase of more than five cold wave days per decade, and in few places by over 15 days per decade during the 2011–2021 period.
• Over India’s core cold wave regions, a typical winter (December–February) used to see about 4–6 cold wave days on average. In recent decades, some zones especially central and eastern parts of India have shown not only increased frequency of cold wave days, but often a longer overall duration of winter-chill conditions.

Polar Vortex and Its Impact on India’s Climate

• About: The polar vortex is a large-scale ring of winds that circles the polar region. It exists mainly in the stratosphere above 10 km. The vortex traps cold air near the pole. Changes in the vortex can send cold air to lower latitudes.

• • Tropospheric Vortex: The stratospheric polar vortex sits high in the atmosphere. The tropospheric vortex lies near the surface. The stratospheric vortex influences the tropospheric winds. A disturbed stratospheric vortex often leads to surface cold anomalies.

• Mechanism: Planetary waves move north from mid latitudes. Those waves weaken the vortex. The vortex then becomes wavier or splits. The jet stream shifts south because of that change. The southward shift allows polar air to move toward India. A 45 year study in 2025 confirmed strong links between vortex intensity and mid latitude weather.

• Impact: The vortex alters the path of the jet stream. The altered jet stream changes the path of western disturbances. The western disturbances deliver rain and snow to north India. The changed path can also pull cold air into central India.

• • The vortex driven cold spells can affect agriculture. They can affect the health of older adults and children. They can affect energy demand and transport, such events can also help farmers and planners. 

Implications of Cold Waves in India

• Human Health: Cold waves pose serious risks to human health. Cold air stresses the body. Blood vessels constrict when temperature drops. This constriction can raise blood pressure. The risk of heart attacks or strokes grows in older adults and people with heart diseases. Winter also worsens respiratory illnesses. Periodic cold waves have caused thousands of deaths across India between 2001 and 2019. 

• Agriculture: Cold waves threaten the success of winter crops. Frost or sudden low temperatures can damage seedlings or flowering plants. Horticultural crops and vegetables remain especially sensitive. Some staple crops may still tolerate chill if conditions remain stable but frequent or intense cold spells can reduce yield or even cause crop failure. 

• Livestock: Cold waves harm animals and fish as well. Livestock may suffer from cold stress. Birds, poultry, and wild animals also face survival challenges. Cold stress can reduce productivity of dairy or meat production. Fish farms may see fish mortality when water temperature and ambient temperature drop sharply. 

• Economic: Cold waves affect daily wage earners, street vendors, labourers, and the informal sector heavily. Many of these workers operate outdoors but cold weather reduces their ability to work. These impacts put stress on rural and urban poor communities. The cold wave becomes a livelihood shock for many households. 

• Transport: Cold waves often coincide with dense fog and low visibility especially in northern plains. Fog can cause road accidents and hamper road transport. Rail and air services may face delays or cancellations. Cold waves also strain power and energy infrastructure. Demand for heating rises sharply.

Policies and Preparedness to Manage Cold Waves in India

• National Guideline: The National Guidelines for Preparation of Action Plan – Prevention and Management of Cold Wave and Frost, published by the NDMA in 2021, provide a framework for states and districts to prepare their own action plans. These guidelines emphasize a multi-sectoral and multi-dimensional approach to mitigate the impacts of cold waves on various sectors, including public health and agriculture. 

• • Monitoring Systems: The IMD uses several large-scale atmospheric and oceanic indices for forecasting cold waves and seasonal outlooks, including the Madden-Julian Oscillation (MJO). The IMD issues seasonal outlooks and short term cold wave warnings also use model guidance and stratospheric indices to assess risk.

• Health System Readiness: The National Centre for Disease Control (NCDC) released a cold wave public health advisory in January 2024 to enhance preparedness and mitigate health risks. The advisory outlines specific actions for the public, health departments, and hospitals regarding essential medicines, common cases, and surveillance. 

• Agricultural Protection: Agricultural departments issue advisories for crop protection before anticipated cold waves to help farmers mitigate damage. Common recommendations for sensitive crops include using mulching techniques and adjusting sowing schedules to avoid peak cold periods. Authorities provide insurance claim assistance after verified losses.

• Social Protection: Municipal and state agencies set up temporary shelters for the homeless and migrants. Recently, Delhi prepared 197 permanent and 250 temporary shelters in November 2025. Local bodies distribute blankets, warm clothing and hot meals during cold spells. Welfare departments coordinate with NGOs to extend relief to remote communities.