When is it permissible to combine the obligatory prayers due to weather conditions, and has this become a habit in some mosques?

It is permissible to combine the Maghrib and Isha prayers during the time of either of them due to rain that wets clothes and causes hardship, as well as due to cold and mud that cause discomfort to a person. Some jurists also hold the view that it is permissible to combine the Dhuhr and Asr prayers for the same reasons, arguing that the underlying cause is hardship.