Persistent morning fog across India’s National Capital Region is shaping winter conditions for the last week of January 2026, underscoring how visibility disruptions remain one of the most volatile elements of the capital’s cold season.

According to India’s Meteorological Department(IMD), shallow fog and haze are expected during early hours of January 27, limiting visibility before clearing later in the day as sunshine returns. Minimum temperatures are projected to stay between 6 degrees Celsius and 9 degrees Celsius, while daytime highs are likely to hover around 18 degrees Celsius to 19 degrees Celsius.

These readings are broadly in line with seasonal averages, but fog formation remains highly sensitive to night-time cooling, calm winds, and residual moisture following recent rainfall. Historical data illustrates that fog behaviour in Delhi varies sharply from year to year rather than following a stable trend.

IMD records show that some recent winters logged extended spells of dense fog, particularly during December and January, while other seasons saw significantly fewer fog hours despite similar temperature ranges. This variability has made fog a less predictable risk than cold intensity itself. Over longer observation periods, January consistently emerges as the peak month for fog incidence across northern India.

Thirty-year climatological averages indicate that dense and very dense fog events occur more frequently during this period than in November or February, reflecting optimal conditions for moisture retention and temperature inversion over the Indo-Gangetic Plain. This winter’s pattern so far suggests moderate fog persistence rather than extreme accumulation.

Morning visibility is most likely to be affected between 6 am and 10 am, with gradual improvement as solar heating strengthens boundary-layer mixing. Aviation, rail, and road operators typically adjust schedules during these windows, even when fog intensity remains below severe thresholds.

However the possible change in weather around January 27 could temporarily alter conditions, either intensifying fog or dispersing pollutants depending on wind direction and precipitation.