What’s Happening?
The India Meteorological Department (IMD) has issued a dense fog alert for large parts of Punjab, Delhi, and Rajasthan valid June 19–21, 2025. Night‐to‐morning visibility is expected to drop below 200 metres, disrupting road, rail, and air traffic across the Indo‑Gangetic Plains mausam.imd.gov.in.
Why Now?
- Winter Residuals & Moisture: Lingering cool temperatures combined with high relative humidity form a shallow, saturated layer close to the surface—ideal for radiation fog formation.
- Calm Winds: Light winds (below 5 km/h) during pre‑dawn hours enable fog to accumulate rather than disperse.
- Recent Rainfall: Scattered pre‑monsoon showers have moistened the ground, further boosting humidity levels at night mausam.imd.gov.in.
5 Key Takeaways
- Duration & Timing: Fog will be most intense between 2 AM and 8 AM, especially in low-lying areas and river valleys.
- Visibility Impact: Motorists may face “zero‐visibility” conditions (< 50 m) in isolated pockets—exercise extreme caution on highways and rural roads.
- Transport Disruptions: Anticipate delayed flights at Chandigarh, Delhi and Amritsar airports, and potential rescheduling of morning trains.
- Health Advisory: People with asthma or chronic bronchitis should limit outdoor exposure; fog particles can carry pollutants deep into the lungs.
- Preparedness Tips:
- Use low‑beam headlights and fog lamps.
- Maintain safe following distances (at least 100 m).
- Check live traffic apps (e.g., “Indian Rail Info”, “Flightradar24”) before travel.
Expert Analysis
“Persistent radiation fog in late‐June is unusual but not unprecedented. The lull before monsoon onset, coupled with nighttime cooling, creates perfect fog‐forming conditions,” explains Dr. Sanjay K. Mishra, climate scientist at the Indian Institute of Tropical Meteorology (IITM), Pune. Profile mausam.imd.gov.in.
Dr. Mishra adds that while fog typically peaks in December–January, pre‑monsoon fog events can intensify pollution‐trapping effects, raising health concerns in urban centers like Delhi.
Health & Safety Guidance
According to the World Health Organization’s Ambient (Outdoor) Air Quality Guidelines, fine particulate matter (PM₂.₅) in fog can exacerbate cardiovascular and respiratory conditions, increasing hospital admissions by up to 20% during dense‐fog episodes who.int.
- Vulnerable Groups: Elderly, children, and those with lung or heart disease should remain indoors in the early morning.
- Indoor Air: Keep windows closed, use air purifiers where available, and avoid strenuous exercise outdoors.
Daily Digest: Fog Watch
| Date | Region | Advisory Level | Visibility (m) |
|---|---|---|---|
| June 19 | Punjab (Amritsar, Ludhiana) | Dense Fog (Orange) | 100–200 |
| June 20 | Delhi‑NCR | Very Dense Fog (Red) | < 100 |
| June 21 | West Rajasthan (Jodhpur) | Dense Fog (Orange) | 150–250 |
Alerts are updated daily at 5 PM IST by IMD. Stay tuned for the June 20 bulletin.
Fact‑Check
- Monsoon Confusion: Contrary to some social‑media posts, this fog is not linked to an approaching Western Disturbance or cyclonic activity—it’s a local, radiative phenomenon.
- Pollution vs. Fog: While fog can trap urban smog, the event itself originates from natural moisture and temperature dynamics, not industrial emissions.
What Happens Next?
- June 22 onwards: Monsoon winds are forecast to strengthen, likely dispersing fog and ushering in widespread rains.
- Stay Informed: Follow IMD bulletins at mausam.imd.gov.in and official state emergency services for live updates.
