The kharif season varies by crop and region, starting at the earliest in May and ending at the latest in January. In India the season is popularly considered to start in June and to end in October. Kharif crops are usually sown with the beginning of the first rains during the advent of the south-west monsoon season, and they are harvested at the end of monsoon season (October-November). The rabi crops are sown around mid-November, preferably after the monsoon rains are over, and harvesting begins in April / May. The crops are grown either with rainwater that has percolated into the ground, or using irrigation. A good rain in winter spoils the rabi crops but is good for kharif crops.