The cloudy morning atmosphere made the children a little late in coming to study because they were hampered by the rain that fell a few moments before. They had been present before when the rain was not too heavy around this place.
This morning the children were still enthusiastic about taking part in the lesson even though not all of their friends were present. Arriving early means they have to wait for other friends who are still on their way to arrive.
And this waiting has become a habit for them when the current changing weather is uncertain, sometimes it rains and sometimes it's hot. They do it all happily because they can study with their friends.