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.
Fig-3
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 |
|
|
|
Shillong |
29.8 |
12-Feb |
26.0 |
|
|
|
Imphal |
31.5 |
19-Feb |
28.9 |
|
|
|
Panjim |
39.2 |
20-Feb |
36.9 |
|
|
|
Honavar |
38.5 |
20-Feb |
37.5 |
|
|
|
Karwar |
39.1 |
20-Feb |
38.1 |
|
|
|
Vishakhpatnam |
38.2 |
26- Feb |
38.0 |
|
|
|
Adliabad |
38.3 |
28- Feb |
38.3 |
|
|
|
Arogyavaram |
37.0 |
26,27- Feb |
36.8 |
|
|
|
Baptla |
35.4 |
28- Feb |
34.9 |
|
|
|
Hyderabad |
39.1 |
26,27- Feb |
38.0 |
|
|
|
Kurnool |
39.9 |
26,27-Feb |
39.8 |
|
|
|
Medak |
38.0 |
28 -Feb |
38.0 |
28/02/2001 & 26/02/2006 |
|
|
Nalgonda |
39.5 |
25,28 -Feb |
39.5 |
|
|
|
Tirupati |
39.5 |
26,27- Feb |
39.5 |
|
|
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.
|
|
|
|
|
Fig. 5 Monthly
wind anomaly - February 2009