Delhi-NCR is expected to experience cold wave conditions until January 6, with temperatures ranging from 8-10 degrees Celsius minimum and 16-18 degrees Celsius maximum. Rajasthan faces an orange alert for dense fog, with visibility potentially dropping below 100 meters and temperatures falling by 3-4 degrees Celsius between January 4-6. Light rainfall occurred in parts of Rajasthan and Mumbai due to a western disturbance. The city's air quality remains in the 'very poor' category.