Winter could be colder this season due to the prevailing La Nina conditions, India Meteorological Department (IMD) Director General Mrutunjay Mohapatra said on Wednesday, adding that climate change has led to erratic weather. Given a weak La Nina condition is prevailing, a colder winter is very likely, Mohapatra said. While addressing a webinar on ‘Cold Wave Risk Reduction’, he explained La Nina related to the cooling of the Pacific waters is favourable for cold wave conditions, while the El Nino is unfavourable for it. The La Niña weather pattern is formed as the warm water moves west, cold water from the deep rises to the surface near the coast of South America.