As the weather cools with the arrival of autumn, people are once again considering when to turn on their heating systems. For those living in single-family homes, this decision is personal, but for apartment dwellers, it may depend on the collective choice of their building’s management. The timing for starting heating varies depending on several factors, such as where someone lives, the design of their home, the level of insulation, and the local climate. Traditionally, heating has been turned on around October 15th and turned off around April 15th, but these dates are becoming less reliable due to climate change. In recent years, it has been common for heating to be activated later than October 15th, and unpredictable weather patterns can cause earlier or later use. No major cold snap is currently expected. For optimal comfort, it is suggested to start heating when indoor temperatures remain around 19°C for several days in a row, which is usually linked to similar outdoor temperatures. In the coming days, the national thermal indicator will temporarily fall below average, hovering between 12 and 14°C before rising above average in the following days. Some people might feel inclined to turn on their heating, while others, who are less sensitive to the cold or concerned about costs, might wait a few more days. The Unified Degree Days (DJU) measure the difference between the average daily temperature and a threshold of 17°C. This index helps estimate heating needs and is calculated daily to determine monthly and annual averages during the "heating season," which runs from January to May and from October to December. If the DJU index is higher than 1, it means the climate is more severe than the average from 1991 to 2020. Since 2013, three years—2013, 2016, and 2021—have been more severe than average. Although September is not included in these calculations, early temperature drops, like those in 2017 and 2024, can still occur. To reduce heating consumption, simple measures can be taken to maintain indoor temperatures without activating the heating or by limiting its use. These include closing windows, doors, and shutters well during the night and opening them during the afternoons when the sun is out. If heating is used, it should be adjusted according to the rooms: 19°C during the day for the living room and kitchen, and 17°C in the bedrooms. At night or when away, the temperature in the living room and kitchen can be lowered by 3°C. As the weather transitions into autumn, the question of when to turn on heating becomes urgent. While some people feel the need to warm their homes, others may wait a few more days. Each region and home has its own specific conditions, and each person must adapt based on the temperatures and weather forecasts. In addition to heating, another topic of concern this weekend will be the change of wardrobe.