This year the pre monsoon period has been atypical for Lahore so far. Right from the middle of march which marks the onset of this season to date there have been major anomalies of temperatures.
To start with, the middle of March started with normal temperatures. Then about the first decade of the month, an exceptionally strong heat wave commenced with shot up the day time temperature to 110 F by the end of March-a temperature unknown in Lahore in the month of March for at least past six decades.
Then came the month of April. Its first decade saw the demise of the heat wave and the temperatures were restored to the normal. A few days passed with normal to near normal temperatures then suddenly the temperatures began to rise and in three days the temperatures of the day time rose from 95 F to 110 F and the following day the temperatures reached 113 F. This is very high even for April’s standards.
A western disturbance came to the rescue that brought down the temperatures so much so that the maximum temperatures went below 90 F and stayed there for 48 hours. Hardly the laborites had heaved a sigh of relief than another severe heat wave started in the early days of May 2017. By 6th the temperatures had reached 110 F and by 7th it was towering 113 F again. Then a strange thing happened. A shallow westerly system reached Lahore and high velocity gusty winds full of dust began to blow and the very next day temperatures was 109 F. One day more passed and it was 106. Yesterday that is 10th of May 2017 the temperatures dropped to 104 F and strong winds of 20-30 knots blew from WNW the whole day.
Near sunset, the same day a moderate dust storm came and the temperature dropped a little. Then at about 9 pm a severe dust storm came with gust reached 40 knots or so. The whole atmosphere was charged with dust and it was difficult to breathe even.
In short such huge fluctuations in temperature in such a short span of time are unknown in Lahore in the pre monsoon period. It is apprehended that if such a pattern remains intact, it will disturb the monsoon rainfall of Lahore. Lahore and other central Punjab locations get 70 percent of their total annual rainfall from monsoon and the rice crop in central Pakistan is heavily dependent on the reliability and amount of monsoon rainfall. Whenever monsoon pattern is disturbed in a certain year; it directly affects the rice production.
To sum up, this year the period prior to monsoon has been very un predictable as far as temperature figures are concerned and the major concern it that it may affect the onset as well rainfall of monsoon season which is very vital for the rice crop; Pakistan being primarily an agro based economy.
The Distribution of Monsoon Rain in Pakistan
The Arrival Of The South West Monsoon
The Premonsoon Season