Despite the formal exit of the northeast monsoon which usually heralds the setting of winter-like conditions over Kerala, the State is yet to witness nippy mornings, the distinctiveness of December and January months. The back-to-back weather systems formed over the Bay of Bengal and the Arabian Sea, coupled with the drying effect of El Niño, are said to be keeping the mercury above the normal mark in Kerala.
In fact, winter in Kerala is very mild compared to north India, due to the maritime effect on the State along with the towering presence of the Western Ghats on the eastern side which prevents the intrusion of the cool northerly from the Himalayan glaciers. For most parts of Kerala, except for some pockets in hill stations such as Munnar in Idukki where the mercury touches sub-zero levels, winter is something like just cool mornings and then generous sunny weather during the remaining daytime. However, the overnight chill and misty mornings which are the specialty of the season is conspicuous by its absence this time around.
Both the minimum and the maximum temperatures have been ruling above the normal mark in most parts of Kerala in the first week of January.
Isolated rainfall
According to experts from the India Meteorological Department (IMD), misty mornings usually appear when the atmosphere is stable. However, the instability caused by the weather systems over the Bay of Bengal and the Arabian Sea has been triggering isolated rainfall across the State for some time. Further, the influence of El Niño that prevails over the equatorial Pacific is expected to contribute to the warmer days and nights here, they said.
For instance, summer in the northern hemisphere is in June. But more rain comes in July only. This lag is because of the time taken to heat the atmosphere. Similarly, the effect of El Niño may also be delayed after its formation. In addition, the Positive Indian Ocean Dipole (IOD), which offsets the negative impact of El Niño event, remains active, but it is weakening steadily, which will also have a bearing on the weather along the west coast, said the experts.
It is, however, expected that after the first two weeks of January, the minimum temperature is likely to drop. However, the monthly forecast issued by the IMD warned of above-normal minimum and maximum temperatures across Kerala during January, indicating that the days ahead of the summer are likely to be a bit harsher this year (2024).