Schools in Delhi-NCR largely operated under online or hybrid learning modes on Monday, January 19, 2026, as stringent anti-pollution measures under Stage IV of the Graded Response Action Plan (GRAP-4) were enforced. The Commission for Air Quality Management (CAQM) invoked GRAP Stage IV on Saturday, January 18, 2026, after the national capital's Air Quality Index (AQI) deteriorated significantly, breaching the 400-mark and entering the 'severe' category. Delhi recorded an average AQI of 440 on January 18, making it the most polluted January day in two years. By Saturday evening, the AQI had further risen to 428 in Delhi, leading to a proactive decision to implement GRAP-4 measures across the entire National Capital Region to prevent further deterioration of air quality. Under GRAP Stage IV, several restrictions were imposed, including a ban on non-essential construction and demolition activities, and restrictions on the entry of non-essential BS-IV diesel goods carriers into Delhi. Regarding schools, while there wasn't a blanket closure order from the Delhi government for all institutions, GRAP-4 guidelines mandated a switch to online classes for Nursery to Class 5 and recommended a hybrid learning approach for Classes 6 to 12 in Delhi and other major NCR cities. Consequently, many individual private and public schools communicated directly with parents, announcing a shift to online classes for January 19. However, schools in Noida and Greater Noida specifically maintained physical classes, but with revised timings from 10:00 AM to 3:00 PM, primarily due to dense fog and extreme cold conditions rather than pollution-specific closures for all grades. This period marked Delhi's worst January air quality spell in five years, with three consecutive days of severe air pollution.