Northern India Gripped by Cold Wave and Dense Fog; Western Disturbance Expected
Northern India faces cold wave and dense fog, with a Western Disturbance bringing rain and snow.
Photo by Brian Yurasits
Quick Revision
Northern India experiencing cold wave and dense fog.
129 flights cancelled at Delhi airports due to fog.
Western Disturbance expected from December 25 in J&K and Himachal Pradesh.
'Chillai Kalan' (40-day harsh winter) began in Kashmir.
IMD issued red alert for UP for dense fog and cold day.
Pulwama recorded minimum of minus 3.2 degrees Celsius.
Key Dates
Key Numbers
Visual Insights
Northern India: Cold Wave, Dense Fog & Western Disturbance Impact (Dec 2025)
This map illustrates the regions in Northern India currently affected by severe cold wave conditions and dense fog, along with the typical trajectory of a Western Disturbance influencing the weather.
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Key Impacts of Northern India's Cold Wave & Fog (December 2025)
A snapshot of the immediate consequences of the severe cold wave and dense fog gripping Northern India.
- Flights Cancelled (Delhi)
- 129N/A
- Chillai Kalan Duration (Kashmir)
- 40 DaysN/A
- IMD Alert Level (Uttar Pradesh)
- Red AlertN/A
- Visibility Reduction
- <200 metersN/A
Indicates severe disruption to air travel due to poor visibility caused by dense fog and pollution.
Refers to the harshest winter period in Kashmir, characterized by extreme cold and freezing temperatures, impacting daily life and water resources.
Issued for dense to very dense fog and cold day conditions, signifying a need for immediate action and high impact.
The threshold for 'dense fog', severely affecting road, rail, and air transport safety.
Exam Angles
Physical Geography and Climatology: Understanding Western Disturbances, jet streams, fog formation, cold wave phenomena, and regional climatic variations.
Environment and Ecology: Interplay of air pollution with meteorological conditions (smog), Air Quality Index (AQI), and health impacts of extreme weather and pollution.
Disaster Management: Role of IMD in early warning systems, preparedness for extreme weather events, and impact on infrastructure and public life.
View Detailed Summary
Summary
Northern Indian states are experiencing severe cold wave conditions and dense fog, leading to reduced visibility and affecting normal life, including the cancellation of 129 flights at Delhi airports. The national capital is under a cold wave, with pollutants also contributing to poor visibility. Jammu & Kashmir and Himachal Pradesh are bracing for rain and snow, with a fresh feeble Western Disturbance expected to affect the region from December 25.
Kashmir's 40-day harsh winter period, 'Chillai Kalan', has begun, with temperatures plummeting. The IMD has issued a red alert for dense to very dense fog and cold day conditions in Uttar Pradesh, and similar conditions persist in Punjab, Haryana, and Rajasthan.
Background
Latest Developments
Currently, northern Indian states are experiencing severe cold wave conditions and dense fog, leading to widespread disruptions, including flight cancellations and reduced visibility. This situation is compounded by air pollutants in urban areas, contributing to poor visibility and health concerns.
A fresh, albeit feeble, Western Disturbance is anticipated, which typically brings rain and snow to the Himalayan region and further intensifies cold conditions in the plains. The India Meteorological Department (IMD) has issued red alerts, highlighting the severity of these weather events.
Practice Questions (MCQs)
1. With reference to Western Disturbances (WDs) affecting India, consider the following statements: 1. They are extratropical storm systems originating in the Mediterranean region. 2. They are primarily responsible for winter rainfall in the Indo-Gangetic Plains and snowfall in the Himalayan region. 3. The movement of WDs across India is influenced by the Subtropical Westerly Jet Stream. Which of the statements given above is/are correct?
- A.1 only
- B.2 and 3 only
- C.1 and 3 only
- D.1, 2 and 3
Show Answer
Answer: D
Statement 1 is correct: Western Disturbances are indeed extratropical storms originating in the Mediterranean Sea, moving eastward across Iran, Afghanistan, and Pakistan before reaching India. Statement 2 is correct: They are the primary source of winter precipitation (rain in plains, snow in mountains) in North and Northwest India. Statement 3 is correct: The Subtropical Westerly Jet Stream plays a crucial role in guiding these disturbances across the Indian subcontinent. Therefore, all three statements are correct.
2. Consider the following statements regarding cold wave and fog conditions in Northern India: 1. A 'cold wave' is declared when the minimum temperature falls below a certain threshold and is significantly lower than the normal temperature for that region. 2. Dense fog formation is often facilitated by temperature inversion, high humidity, and the presence of abundant condensation nuclei. 3. 'Chillai Kalan' is a 40-day period of intense cold observed traditionally in the Ladakh region of India. Which of the statements given above is/are correct?
- A.1 and 2 only
- B.2 and 3 only
- C.1 only
- D.1, 2 and 3
Show Answer
Answer: A
Statement 1 is correct: IMD defines a cold wave based on minimum temperature deviation from normal or absolute minimum temperature thresholds. For plains, it's typically when the minimum temperature is 10°C or less and 4.5°C to 6.4°C below normal, or when the minimum temperature is less than or equal to 4°C. Statement 2 is correct: Temperature inversion traps moisture and pollutants near the surface, high humidity provides water vapor, and condensation nuclei (like dust, smoke, pollutants) provide surfaces for water droplets to form, all contributing to dense fog. Statement 3 is incorrect: 'Chillai Kalan' is a 40-day period of harsh winter primarily observed in the Kashmir Valley, not Ladakh. The news explicitly mentions 'Kashmir's 40-day harsh winter period, 'Chillai Kalan', has begun'.
3. In the context of meteorological alerts issued by the India Meteorological Department (IMD) and related atmospheric phenomena, which of the following statements is NOT correct?
- A.A 'Red Alert' signifies that authorities should take action to protect lives and property from severe weather conditions.
- B.Smog is a type of fog that is intensified by the presence of air pollutants, particularly particulate matter.
- C.A 'cold day' condition is declared when the maximum temperature is significantly below normal, even if the minimum temperature is not exceptionally low.
- D.Radiation fog typically forms over land on clear nights with strong winds, leading to rapid cooling of the ground.
Show Answer
Answer: D
Statement A is correct: IMD's color-coded alerts (Green, Yellow, Orange, Red) indicate increasing levels of severity and the need for preparedness and action. Red alert is the highest level, signaling 'take action'. Statement B is correct: Smog is indeed a combination of smoke and fog, where pollutants (like PM2.5, PM10) act as condensation nuclei, making the fog denser and more persistent, especially in urban areas. Statement C is correct: A 'cold day' is declared when the maximum temperature is significantly below normal (e.g., 4.5°C to 6.4°C below normal) and also below a certain absolute threshold (e.g., 16°C for plains), even if the minimum temperature doesn't meet cold wave criteria. Statement D is incorrect: Radiation fog typically forms over land on clear, calm nights (light winds or no wind) when the ground cools rapidly by radiation, cooling the air directly above it to its dew point. Strong winds would mix the air and prevent the formation of a stable fog layer.
Source Articles
Delhi Weather: Temperatures plummet across north India, people wake up to light rain in Capital City - The Hindu
Snow, rain likely as Kashmir braces for 'Chillai-Kalan' - The Hindu
North India continues to reel under cold wave conditions; no 'white Christmas' in Srinagar, Shimla - The Hindu
Snowfall disrupts normal life in Himachal, J&K; rainfall in parts of north India intensifies winter chill - The Hindu
Incessant rain and flood disrupt life in northern India - The Hindu