October is supposed to be dry in most of India. But this year the rain has not stopped. Kerala and Tamil Nadu are getting heavy rain. Bihar has a yellow alert for 26 districts. Uttarakhand and Himachal Pradesh are also under rain alerts. So why is it raining in October?

The answer is the western disturbance. This is a weather system that comes from the west. It usually brings winter rain to the north. This week it has become active over north India. It is pushing moisture into the hills and the plains.

The southwest monsoon is also withdrawing late. It began retreating on September 19. But the withdrawal is slow. It is still moving through Bihar and Jharkhand. As the monsoon pulls back, post-monsoon weather systems can still bring showers.

For travellers, the advice is simple. Check the IMD’s district warnings before heading to the hills. In Kerala and Tamil Nadu, avoid sea travel during alerts. In Delhi, the rain may actually help. It is washing out some of the October pollution.