Delhi and the National Capital Region (NCR) are shivering under unusually low daytime temperatures, prompting the India Meteorological Department (IMD) to issue a yellow alert for the next two days. Alongside the cold, air quality in the capital has deteriorated to “very poor” levels, reaching an AQI of 336, highlighting the combined challenges of winter weather and pollution.

Reason Behind Lower Daytime Temperatures

IMD officials explained that the drop in daytime temperatures is largely due to a persistent upper-level fog combined with cold northwesterly winds sweeping across northern India. According to IMD scientist Naresh Kumar, a dense fog layer, described as a “clear clouds dense fog layer,” prevents sunlight from reaching the ground, inhibiting warming during the day.

“This layer blocks direct solar radiation, which is why even daytime temperatures are lower than normal,” Kumar said. As a result, the IMD has issued cold wave and “cold day” warnings for several northern states, including Punjab, Haryana, Uttar Pradesh, and Bihar. Early morning temperatures have been particularly low, with readings around 4 degrees Celsius or even lower in Punjab and Haryana.

Impact on Delhi

In Delhi, parts of the city recorded “cold day” conditions on Tuesday, and temperatures are expected to remain subdued until at least January 15. According to IMD data from Safdarjung observatory, the capital logged a maximum temperature of 15.7°C and a minimum of 8.6°C on Wednesday. The weather department has issued a yellow alert until Thursday, warning residents of dense to very dense fog during morning and forenoon hours, which could reduce visibility and affect road and air travel.

Air Quality Concerns

Amid the cold wave, Delhi’s air quality has worsened significantly. Data from the Central Pollution Control Board’s (CPCB) Sameer app showed the air quality index (AQI) rising to 336, placing it in the “very poor” category. Nehru Nagar recorded the worst pollution levels in the city, with an AQI of 360.

The combination of cold, stagnant air and lingering pollutants has prevented dispersion, contributing to the poor air quality. On Tuesday, the AQI had been slightly better, recorded in the “poor” range, but the worsening conditions highlight the persistent challenge of winter pollution in the capital.

Precautionary Measures

IMD has urged residents to take precautions, especially during early morning and evening hours when temperatures are lowest and fog reduces visibility. People are advised to wear warm clothing, limit outdoor exposure, and be cautious while commuting. Authorities are also expected to monitor pollution levels closely, as the combination of cold and dense fog can exacerbate respiratory issues, particularly for vulnerable populations such as children, the elderly, and those with pre-existing conditions.

Northern India Under Cold Wave

The yellow alert covers not only Delhi but also several northern states. Punjab, Haryana, and Uttar Pradesh have been issued cold wave warnings for the next two to three days, and Bihar is also likely to experience a similar drop in temperatures. IMD forecasts suggest that the cold conditions may persist, with night and day temperatures remaining below seasonal averages, primarily due to the dense fog layer and persistent northwesterly winds.

In summary, northern India, particularly Delhi-NCR, is grappling with a combination of low temperatures, dense fog, and deteriorating air quality. The IMD has issued timely warnings to help residents take necessary precautions as the cold wave continues over the coming days.