Mumbai is currently experiencing a milder winter compared to typical seasonal patterns. While January usually marks the coldest month with minimum temperatures frequently dropping to the mid-teens, December has maintained an average of approximately 18°C. The lowest recorded temperature so far, according to the Santacruz airport observatory, was 19.4°C on December 13th and 16th, with temperatures consistently remaining above 20°C on other days.
This morning, the observatory registered the highest minimum temperature in the last two weeks at 23.6°C, a substantial 6°C above the normal range. Despite a low of 23.8°C on December 5th, there has been a lack of the expected seasonal progressive drop in mercury from the beginning to the middle of the month.
The absence of an active western disturbance affecting the northern plains and hills has contributed to the current weather conditions. Weak weather systems passing across the mountains, except for one on December 16th and 17th, have not brought significant cold winds to the plains, South Rajasthan, Gujarat, and Maharashtra. The anticyclone over Rajasthan, with an uncertain and weak wind pattern, has not facilitated the transport of cold air from mountain slopes to central regions.
While there has been a noteworthy drop in mercury levels in isolated areas of Punjab, Haryana, and Delhi, sustained cold conditions have been limited. The wind pattern is not expected to favor chilly conditions, and a weak system is anticipated for Rajasthan around December 22nd. Another mild western disturbance is likely between December 23rd and 25th, maintaining unsettled conditions for at least the next week. Temperature drops in Maharashtra, including Mumbai, are expected to be minimal over the next three days.
Compared to last year when Mumbai experienced its lowest minimum temperature of about 15°C around Christmas, this December has yet to witness sweeping winds from the plains of North India. The city has predominantly experienced warm winds from the sea or easterly/southeasterly winds from the land. The absence of persistent northerly or northeasterly winds suggests that Mumbai may continue without the typical wintry ambiance for at least another week or more.