A report on exceptionally high temperatures during February 2009

 

February is the last month of winter season in India.  Being a transition period from winter to summer, the weather over most parts of the country is normally very comfortable.  However, this year the temperatures during February 2009 were exceptionally high.

 

State-wise mean monthly temperature scenario

Mean maximum temperatures for the month were above normal by 2- 4ēC  over most parts of central , adjoining east & peninsular India, northeastern states  & western Himalayan region and parts of plains of northwest India (Fig-1).

Fig-1:  Mean maximum temperature (ēC) anomaly for February 2009

 

 Mean minimum temperatures of the month were also above normal by 2-4ēC over many parts of Rajasthan & Gujarat, some parts of Punjab, Madhya Pradesh, Madhya Maharashtra and isolated pockets of Chhattisgarh, Orissa, Sikkim, Arunachal Pradesh, Assam, Marathawada, Vidarbha and Bihar (Fig-2).

  Fig-2:  Mean minimum temperature (ēC) anomaly for February 2009

 

Station-wise mean monthly temperature scenario

Mean monthly temperatures were also above normal during the month at many stations. Except for the minimum temperature of Ranchi, all the stations have recorded above normal maximum, minimum and average temperatures ranging   from 1- 4 ēC during February 2009 (Table-1).

Station

Max. Temp.

Min. Temp.

Average Temp.

Actual

Normal

Actual

Normal

Actual

Normal

Delhi

26.1

24.2

11.1

10.1

18.6

17.1

Amritsar

23.2

22.5

7.5

6.5

15.4

14.5

Chandigarh

25.0

23.3

11.4

9.1

18.2

16.2

Srinagar

11.1

7.8

1.6

- 0.7

6.4

3.6

Shimla

15.7

10.5

6.2

3.2

11.0

6.8

Dehradun

24.7

21.5

9.6

8.1

17.1

14.8

Jaipur

28.6

25.5

13.3

10.7

20.9

18.1

Lucknow

27.6

26.0

11.3

9.8

19.5

17.9

Patna

28.3

26.6

12.8

12.1

20.5

19.4

Raipur

34.0

30.4

18.7

16.1

26.4

23.2

Ranchi

29.3

25.1

12.4

12.5

20.8

18.8

Bhubaneswar

35.1

32.0

20.6

18.5

27.8

25.3

Bhopal

31.0

28.5

14.4

12.5

22.7

20.5

Nagpur

35.3

32.3

17.5

15.1

26.4

23.7

Pune

34.2

32.0

13.1

11.6

23.6

21.8

Ahmadabad

32.4

31.1

16.2

14.5

24.3

22.8

 

 

 

 

 

 

 

 

 

 

 

 

 

Table-1: Mean monthly temperature during February 2009

 

Markedly above normal temperatures at many stations

The maximum temperatures at some of the stations in Orissa and Maharashtra reached or even crossed the 40 ēC mark. A large number of stations reported maximum temperatures which were above normal by more than 5 ēC on a day to day basis (Fig-3). Similarly, Fig. 4 shows the number of stations which reported minimum temperature departures of the order of + 5ēC and above.

NDC DATA_29709_image001

Fig-3

 

NDC DATA_32366_image001

Fig-4

All time warm February 2009 at some stations

During the month, the all time record of highest maximum temperatures was broken at many of the stations.  Table-2 gives the details of stations recording maximum temperatures during February 2009 higher than their all time previous records.

 

 

Station

Maximum Temperature

 (2009)

Maximum Temperature

(All time previous records)

oC

Date

oC

Date

Darjeeling

19.4

10-Feb

18.3

26/02/1969

Shillong

29.8

12-Feb

26.0

16/02/1969

Imphal

31.5

19-Feb

28.9

28/02/1975

Panjim

39.2

20-Feb

36.9

25/02/1975

Honavar

38.5

20-Feb

37.5

19/02/1977

Karwar

39.1

20-Feb

38.1

14/02/1962

Vishakhpatnam

38.2

26- Feb

38.0

22/02/1967

Adliabad

38.3

28- Feb

38.3

21/02/2006

Arogyavaram

37.0

26,27- Feb

36.8

18/02/2005

Baptla

35.4

28- Feb

34.9

22/02/1990

Hyderabad

39.1

26,27- Feb

38.0

26/02/2001

Kurnool

39.9

26,27-Feb

39.8

23/02/1969

Medak

38.0

28 -Feb

38.0

28/02/2001 &  26/02/2006

Nalgonda

39.5

25,28 -Feb

39.5

15/02/2005

Tirupati

39.5

26,27- Feb

39.5

27/02/2001

 

            Table-2. Stations with temperature exceeding their previous records

 

The possible causes for high temperatures

The atmospheric circulation features which led to the rise in temperatures over various parts of the country are as follows:

1.            Western disturbances affected only western Himalayan region and did not cause any significant rainfall activity over northwest plains and central India.

2.            Due to persistent presence of strong anticyclone over the Arabian Sea, there was warm air advection which led to anomalous above normal temperatures.  Also clear sky conditions due to lack of rainfall activity had contributed to high day temperatures.  Figs. 5 depict the monthly wind anomaly patterns.

           



Text Box:

700a

500a

300a

Fig. 5 Monthly wind anomaly - February 2009