Isolated from much of India by the Western Ghats, the climate of Kerala is tropical and as a result of the mountain ranges the area isn’t as dry as much of India. The temperatures seldom go much above the lows 90s (35-37 degrees celsius) in the summer, but almost never below 70(20-22 degree celsius) in the winter. The high ranges of Kerala experience a range of 50-70 (10 - 24 degree celsius).Thus it is a region of very reasonable weather with mainly four seasons : summer , winter and two monsoon seasons. Although the majority of travellers visit kerala around the winter season starting in December , many seasoned travellers and locals recommend the two monsoon seasons as the best time to visit ( ideally towards the end of the first monsoons or during the second monsoons by which time many of the waterfalls will be in all their glory ie from August  )

The summertime comes a bit early and lasts from March through early June. While there can be the occasional light showers these are just a prelude of the wet weather to come. The weather is generally hot and humid during this early summer. Although there are travellers who visit and many famed trips like the keralablogexpress is generally conducted at this time, the weather can be hot and humid during this time sometimes even going above 37 degrees celsius.

Although the state has rains all year round , Kerala experiences two monsoon seasons: the main season from June - August and the second , from October to November. The first monsoon season arrives in June and continues till August. Depending on the part of Kerala there can be vast amounts or rain, or for some of the outlying islands almost none at all. But when hit by the monsoons there can be truly vast amounts of rain, and these storms can be quite intense. 

September is much more humid as a result of the rainy season, and the fall can be dry but with the humidity this makes it feel quite the warm. You can expect rains in September as well but this is an ideal break between the first and the second monsoon seasons. The harvest festival of Kerala which is the main state festival : Onam , happens in September.  

The second monsoon starts by October and continues till late November. Although this monsoon provides comparatively lesser rain ; this can also be a good time to visit.   Many seasoned travellers recommend the two monsoon seasons to be the best time to visit Kerala as during monsoon , the region receives good rainfall with intermittent sunlight. The monsoons can also be the ideal time to experience Ayurveda in its homeland as the humid air makes the massages and treatments more effective.

The temperatures cool down and the humidity lets up as winter comes in around December, with this season lasting until February when the dry spring returns. Winter can be a pleasant time to visit, especially if you’re looking to head off the beach and explore this Indian land of mystery like the majority of the tourists. There will be rains during this time of the year as well.