Climate of Mumbai

The Climate of Mumbai is a tropical wet and dry climate. Mumbai's climate can be best described as moderate temperatures with high level of humidity. Its coastal nature and tropical location ensures moderate temperatures throughout the year, average of 27.2°C and average precipitation of 242.2 cm (95.35 inches)^[1]. The temperatures in average about 30°C in summer and 18°C in winter. Mumbai's experiences 4 distinct seasons Winter: (December-Feb); Summer: (March-May); Monsoon (June-Sep) and Post Monsoon (Oct-Dec).

Monthly break up of climate

The following is the monthly breakup of the weather in Mumbai.

January

January is the coolest month of the year for Mumbai with mean daily minimum being 16.4°C and mean daily maximum being 30.6°C^{[2] [3]}. The weather is generally mild and pleasant with daytime highs of around 27°C and night-time lows of around 17°C. The nightly lows may vary between 10°C and 20°C. Chilly northern winds during the day make the city seem cooler than it really is. Generally clear skies, with some smog - especially in the early morning - are the norm. The days are dry, the nights relatively humid. January is also associated with the deciduous trees in the city shedding their leaves. January 26-27, 2008 recorded a minimum temperature of 10.2°C, which is the lowest recorded in 45 years.

February

The fine January weather continues for the first fortnight of February. The mean daily minimum stays at 17.3°C and mean daily maximum being 31.3°C ^[2]. The day highs average 29 to 30 °C. The nights hover around 17 °C. By the second fortnight the humidity starts to increase and the day temperature might rise up to 32 °C. Smog increases. February 6, 2008 recorded a minimum temperature of 9.4 °C. Just two days later, on February 8th, the minimum temperature recorded was 8.5 °C, which was the lowest temperature Mumbai has seen since 1962 ^[4]. This was the coldest day in February ever.

March

The month of March sees a mean minimum temp of 20.6°C and mean maximum temp of 32.7°C^[2].The beginning of March sees night temperatures reach 15 °C. The days reach 30 to 33 °C. During the transition from the dry to humid weather in mid March, the temperature might hit 38 to 40°C. This high however, is due to hot dry winds from Gujarat. By mid March the temperatures hit 37 °C, with the lows at 18 °C. Humidity is unbearable, and smog affects the city. New leaves sprout from deciduous trees.

April

The temperatures and humidity are still high. However the cooling effect of sea breezes makes its presence felt. The cool winds compensate for the heat. The mean day highs stay at 33.1°C and mean daily lows are about 23.7°C^[2]. Plants are in full bloom in April.

May

May is the hottest month of the year for Mumbai with the cool sea breezes providing some relief. The mean daily maximum hovers around 33.3°C and mean daily low is 26.1°C^[2]. In May schools are closed for summer vacation. However certain schools like the Dhirubhai Ambani International School prefer to keep their school on till end of June.

June

The Mumbai climate hot weather of May continues into June with some pre-monsoon showers providing some respite. The first rains however, are generally preceded by heavy thunderstorms which signal the onset of the monsoon season in the city. Monsoons hit the city on 9 June, the official date. June sees a substantial amount of rainfall. At the start of the wet season, the weather is unsettled, with rain and sunshine. The max and min mean daily temperatures are measured at 31.9°C/25.8°C. ^[2]

July

Waterlogging due to showers

In this month the city receives the maximum amount of rain. July and August are characterised by almost non stop rain and weeks of no sunshine. During the peak, around late July, it may rain non stop for a week. A continuous monsoon current is witnessed in the city through July. This is characterised by steady winds from the sea and almost continuous rainfall. Parts of Central and Suburban Mumbai are below the sea level at high tide (over 4 meters), these parts tend to be waterlogged as the drains cannot cope with the persistent precipitation. It is not uncommon for the city's public transport to come to a halt during periods of heavy rain.

The rainy season also marks an increase in health related problems caused by water borne diseases. The highs stay around 29.8°C and Lows 24.8°C.^[2] The highest rainfall was also recorded in this month on 26/7/2005 which measured 944 mm ^[5].

August

The weather in August is almost identical to July. Towards the latter half of the month, rainfall activity tends to lessen. The coolest days of the monsoon season are often in August. The max temperature might drop to 29.3°C and the night at 24.5°C.^[2]

September

In September the intensity of rainfall decreases. The monsoons officially end in the 3^rd week of September. September has unsettled weather. The rainfall is short and light and is not continuous. The end of the monsoon, much like the beginning can feature heavy thunderstorms associated with the withdrawal of the monsoon current from the city and surrounding areas. The mean maximum daily temperatures reach 30.1°C while daily mean minimum daily temperature stays at 24.0°C.^[2]

October

In the month of October the mean daily maximum stays at around 32.9°C and mean daily minimum stays at 23.1°C^[2] making it hot during the days and cold during the nights.

November

The temperature continues to drop slowly in the month of November with the mean daily minimum staying at 20.5°C and the mean daily maximum staying around 33.4°C.^[2] There are a few unseasonal showers.

December

The day highs hover around 32.0°C. The nights in the beginning of December do not fall below 18 °C. By late December the day temperature ranges between 28-31 °C. The nights may dip to 12 °C in late December but average around 18.2°C^[2]. Humidity is low in December.

Weather monitoring stations

Mumbai has two weather monitoring stations, one at Santacruz Airport and the other at Navy Nagar near Colaba towards the southern tip of Mumbai.

References