It is possible to install a concrete sidewalk in cold weather but it requires additional precautions and considerations. Cold temperatures can negatively affect concrete’s curing process and overall strength development. Ideally, the air and ground temperatures should rise above 40°F (4°C) for proper curing. In colder conditions, contractors may use various techniques to protect the concrete, such as insulating blankets, adding accelerators to the mix, or using heated enclosures. It’s essential to consult with an experienced concrete professional to ensure proper installation and curing in cold weather conditions.