The climate is equable and varies little from season to season. The temperature normally ranges between 27º and 32º C in the plains but drops to about 21º C in the highlands. The diversity of the geographical features of the state has resulted in a corresponding diversity in climate. The High Ranges have a cool and bracing climate throughout the year, while the plains are hot and humid.The average level of annual rainfall is quite high when compared to other Indian states, almost three times higher than in Karnataka while twice than in Tamilnadu. The state basically enjoys 4 types of climate such as Winter ,Summer ,South West Monsoon and North East Monsoon .

South West Monsoon
The South West Monsoon begins either in the end of May or in the beginning of June and fades out by September. Moving towards north, this seems to gain intensity. During this period Peerumedu in Idukki and Vaithiri-Kuttiyadi range in Malabar receive the highest rainfall. The rainfall is comparatively low in the Lakshadweep islands. In the southern areas the monsoon is around 40-50% and in the northern areas it is around 80%.

North East Monsoon
The NorthEast Monsoon commences in October, dry weather setting in by the end of December. The Kanjirappalli-Peerumedu range and Kuttiyadi area experience the abundance of NorthEast Monsoon. The northern parts of the state account for a mere 10% of the annual rainfall.