October, March and April are considered as the best months to visit Ooty. During these months, the temperature is at a tolerable level of 25 degrees thus making it easier for sightseeing as well as for traveling. The nights during these three months are also comfortable, and one does not require heavy woolens to keep themselves protected from the cold at night.
Summers in Ooty start from the end of March and continue until the first week of May. However, the summers are not hot and humid unlike the rest of south India. The temperature in summers does not go beyond 25 degrees Celsius. The day can become a little hot depending on the time you decide to venture outside, but the nights are definitely cool and pleasant.
Monsoon in Ooty begins in the first week of May and lasts until the end of September. The temperature dips down to about 20 degrees Celsius during the monsoons. The place receives heavy rainfall throwing life out of gear in this hill station. However, the rains do leave the slopes looking greener than ever.
Winter months in Ooty are very cold and dry. Strong winds tend to blow through the day making it difficult to step out of the house without warm clothes. Winters start in the month of October and last until February with January being the coldest month. The temperature during these months dips down to about 4 degrees Celsius at night.