Climate of Kolkata

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Kolkata
Climate chart (explanation)
J F M A M J J A S O N D
 
 
17
 
 
25
9
 
 
23
 
 
30
14
 
 
33
 
 
34
22
 
 
48
 
 
36
25
 
 
102
 
 
36
26
 
 
260
 
 
34
27
 
 
332
 
 
32
26
 
 
329
 
 
32
26
 
 
296
 
 
32
26
 
 
151
 
 
32
24
 
 
26
 
 
30
19
 
 
17
 
 
27
13
Average max. and min. temperatures in °C
Precipitation totals in mm
Source: IMD

Kolkata has a Tropical wet-and-dry climate (Köppen climate classification Aw). The annual mean temperature is 24.8 °C (80 °F); monthly mean temperatures range from 15 °C to 30 °C (59 °F to 86 °F).[1] Summers are hot and humid with temperatures in the low 30's and during dry spells the maximum temperatures often exceed 40 °C (104 °F) during May and June.[1] Winter tends to last for only about two and a half months, with seasonal lows dipping to 9 °C – 11 °C (48.2 °F – 51.8 °F) between December and January. The highest recorded temperature is 43.9 °C (111 °F) and the lowest is 5 °C (41 °F).[1] Often during early summer, dusty squalls followed by spells of thunderstorm and heavy rains lash the city, bringing relief from the humid heat. These thunderstorms are convective in nature, and is locally known as Kal baisakhi (কালবৈশাখী, Nor'westers).[2]

Rains brought by the Bay of Bengal branch of South-West monsoon[3] lash the city between June and September and supplies the city with most of its annual rainfall of 1,582 mm (62.3 inches). The highest rainfall occurs during the monsoon in August (306 mm). The city receives 2,528 hours of sunshine per annum, with the maximum sunlight occurring in March.[4] Pollution is a major concern in Kolkata, and the Suspended Particulate Matter (SPM) level is high when compared to other major cities of India,[5][6] leading to regular smog and haze. Severe air pollution in the city has caused rise in pollution-related respiratory ailments such as lung cancer.[7]


Climate data for Kolkata (Alipore) 1971–1990
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °C (°F) 32.8
(91)
38.4
(101.1)
41.1
(106)
43.3
(109.9)
43.7
(110.7)
43.9
(111)
39.9
(103.8)
38.4
(101.1)
38.9
(102)
39.0
(102.2)
34.9
(94.8)
32.5
(90.5)
43.9
(111)
Average high °C (°F) 26.4
(79.5)
29.1
(84.4)
33.5
(92.3)
35.3
(95.5)
35.4
(95.7)
34.0
(93.2)
32.3
(90.1)
32.1
(89.8)
32.4
(90.3)
32.3
(90.1)
30.3
(86.5)
27.0
(80.6)
31.7
(89.1)
Daily mean °C (°F) 20.1
(68.2)
23.0
(73.4)
27.6
(81.7)
30.2
(86.4)
30.7
(87.3)
30.3
(86.5)
29.2
(84.6)
29.1
(84.4)
29.1
(84.4)
28.2
(82.8)
24.9
(76.8)
20.8
(69.4)
26.9
(80.4)
Average low °C (°F) 13.8
(56.8)
16.9
(62.4)
21.7
(71.1)
25.1
(77.2)
26.0
(78.8)
26.5
(79.7)
26.1
(79)
26.1
(79)
25.8
(78.4)
23.9
(75)
19.6
(67.3)
14.5
(58.1)
22.2
(72)
Record low °C (°F) 6.7
(44.1)
7.2
(45)
10.0
(50)
16.1
(61)
17.9
(64.2)
20.4
(68.7)
20.6
(69.1)
22.6
(72.7)
20.6
(69.1)
17.2
(63)
10.6
(51.1)
7.2
(45)
6.7
(44.1)
Average rainfall mm (inches) 11
(0.43)
30
(1.18)
35
(1.38)
60
(2.36)
142
(5.59)
288
(11.34)
411
(16.18)
349
(13.74)
288
(11.34)
143
(5.63)
26
(1.02)
17
(0.67)
1,800
(70.87)
Average rainy days (≥ 1.0 mm) 1.2 2.2 3.0 4.8 8.7 14.7 20.5 20.2 15.7 8.1 1.5 0.9 101.5
Average relative humidity (%) 66 58 58 66 70 77 83 83 81 73 67 68 71
Mean monthly sunshine hours 203.9 201.2 225.8 235.4 227.1 123.1 93.1 104.9 116.2 182.6 190.8 203.4 2,107.5
Source #1: NOAA[8]
Source #2: India Meteorological Department (record high and low up to 2010)[9]
Climate data for Kolkata
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Mean daily daylight hours 11.0 11.0 12.0 13.0 13.0 13.0 13.0 13.0 12.0 12.0 11.0 11.0 12.1
Average Ultraviolet index 7 9 11 11+ 11+ 11+ 11+ 11+ 11 9 7 6 9.6
Source: Weather Atlas [10]

References[edit]

  1. ^ a b c "Weatherbase entry for Kolkata". Canty and Associates LLC. Retrieved 2006-04-26. 
  2. ^ "kal Baisakhi". Glossary of Meteorology. American Meteorological Society. Retrieved 2006-09-05. 
  3. ^ Khichar, M.L.; Ram Niwas (July 14, 2003). "Know your monsoon". Agriculture Tribune, The Tribune. The Tribune Trust. Retrieved 2007-06-09. 
  4. ^ "Calcutta: Not 'The City of Joy'". Gaia: Environmental Information System. Retrieved 2006-04-26. 
  5. ^ Central Pollution Control Board. "Ambient Air Quality in Seven Major Cities During 2002". Ministry of Environment & Forests, Govt of India. Archived from the original on 2006-02-25. Retrieved 2006-04-26. 
  6. ^ Central Pollution Control Board. "Air quality in major cities on 16–17 March 2006". Ministry of Environment & Forests, Govt of India. Retrieved 2006-04-26. [dead link]
  7. ^ Bhaumik, Subir (17 May 2007). "Oxygen supplies for India police". South Asia. BBC. Retrieved 2007-06-23. 
  8. ^ "Calcutta/Alipore Climate Normals 1971-1990". National Oceanic and Atmospheric Administration. Retrieved December 24, 2012. 
  9. ^ "Ever recorded Maximum and minimum temperatures upto 2010" (PDF). India Meteorological Department. Retrieved May 16, 2014. 
  10. ^ "Kolkata, India - Climate data". Weather Atlas. Retrieved 4 April 2017.