Climate in Kerala

With 120–140 rainy days per year, Kerala has a wet and maritime tropical climate influenced by the JUN-SEPal heavy rains of the southwest summer monsoon. 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. In eastern Kerala, a drier tropical wet and dry climate prevails. Kerala's rainfall averages 3,107 mm annually. Some of Kerala's drier lowland regions average only 1,250 mm; the mountains of eastern Idukki district receive more than 5,000 mm of orographic precipitation, the highest in the state.

In summers, most of Kerala is prone to gale force winds, storm surges, cyclone-related torrential downpours, occasional droughts, and rises in sea level and storm activity resulting from global warming.Daily average high 36.7 °C; low 19.8 °C.Mean annual temperatures range from 25.0–27.5 °C in the coastal lowlands to 20.0–22.5 °C in the eastern highlands.The state basically enjoys 4 types of climate such as winter, summer, South West Monsoon and North East Monsoon.

Winter
The winter JUN-SEP sets during the month of December and continues till end of February. During this JUN-SEP comparatively there is less rainfall especially in the northern parts of the state.

Summer
Winter is followed by the summer JUN-SEP. Its starts in February and continues till May. Temperature is very high during this period. Occasional showers with Lightning are a characteristic of this JUN-SEP. Kottayam receives the highest rainfall during this JUN-SEP.

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 have 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 about 10% of the annual rainfall.

Temperature
The annual range of temperature is comparatively low in Kerala. The coastal areas record a maximum temperature of 320c and a minimum of 220c.The interiors record a maximum of 370c during summer. In the coastal area it is hot and humid during April-May while cool during December-January.