Climate in Kerala

Geographically Kerala is the land of mountains and valleys, evergreen forests cascading waterfalls and palm ringed lagoons Innumerable rivers and river lets criss crossing the countryside towards the west to reach the Arabian Sea. The western ghat on one side and the Arabian Sea on the other side effectively create a unique climatic condition from rest of the country. The wind system in the adjoining Indian Ocean and the Arabian Sea is subject to periodical reversal and controls the day to day weather of our state. The Western Ghats influence the weather very much. The forced ascent of monsoon currents gives rise to heavy rainfall on the windward side of the region. The intensity of the rain is dependent not only on the altitude, but also on the strength and direction of the current as well as the steepness of the slope and other characteristics.

The state doesn’t have to undergo any dry period with the heat of hot, scorching sun like other parts of the country. Summer extends from the month of April to June. During this period the temperature reaches to a maximum of 33 degrees centigrade which is considered less when compared other states of India. The minimum temperature remains within 20 degree centigrade at sea level.

Summer is followed by South West Monsoon that starts pouring in the month of June and continues till September. Though there is no distinct difference in the climatic conditions only with the increase in humidity .Sometimes the downpour may continue persistently even for two or three days. In this period, maximum rainfall is received by Vaithiri-Kuttiyadi range in Malabar and Peerumedu in Idukki. The rainfall is comparatively much less in the Lakshadweep islands. In the northern regions of Kerala, the rainfall is around 80% and in the southern regions the rainfall ranges from 40-50%. Actually the existence of the Western Ghats on the eastern side of the state of Kerala creates a barrier across the path of the southwest monsoon. This resulted in the creation of a significant climatic variation with abundant rainfall on the windward side and a dry belt on the lee eastern side. The North East Monsoon begins in the month of October and stops at the end of December.

With the arrival of winter there is certain drop in the temperature and you can feel a slight chill due to the cold wind. Winter is truly enjoyable in Kerala and lasts from from November to January or February. Occasionally very little rainfall accompanied by thunder and lightning takes place in the northern region of the state. Highest rainfall is received by Kottayam during this winter season

Evidences of Climate change from Kerala

Kerala experienced decline in annual and monsoon rainfall and an increase in temperature during the past decades. The mean annual maximum temperature over Kerala has risen by 0.8 degree centigrade, the minimum temperature by 0.2 degree Celsius and the average by 0.5 degree centigrade between 1961 and 2003 as per the study taken up by the India Meteorological Department. The maximum temperature shot up to 40 degree centigrade in Palakkad during February and March 2004 and the highest of 41 degree centigrade was noticed on April 26, 1950. The year 1987 was the warmest year over Kerala, according to the study. The climate of Kerala is not subject to drastic variations in most meteorological elements. The most significant variations is in respect of rainfall. Variations of temperature are comparatively small. Rainfall and temperature can be employed as the key indicators in arriving at a classification of seasons in Kerala. Summer monsoon rainfall of India and Kerala have considerable inter-annual variability in the date of onset, withdrawal and the activity of the monsoon during the Indian Summer Monsoon Rainfall season. In the case of the northeast monsoon rainfall also, significant inter annual variability is noticed. Summer monsoon rainfall of Kerala shows a decreasing trend of 12.03 cm in 100 years and northeast monsoon rainfall shows an increasing trend 6.6 cm in 100 years. Dry spell during the monsoon season and heavy rains in the summer seasons are not unfamiliar to the land mass in Kerala. These phenomena are part of the climate changes taking place across the world.

Source: Climate Variability in Kerala in Recent Years: Climate Change Perspectives