Lahore, the second largest city in Pakistan, is the first to receive monsoon rains from India. The rains begin around the first week of July and continue until mid-September. Below is a brief sketch of the weather to be expected in Lahore during the monsoons.

Temperature

When the cool and refreshing monsoon winds come from India, the first noticeable effect is the clear drop in air temperature. The maximum temperature that until now was around 100 F falls to 90 F or less. Nights record a similar drop and nightly lows drop from around 80F to 70F.

Of the three months of July, August and September, July is the warmest. August becomes pleasant due to the fact that it is the peak of the monsoon in this month. As for September, the first decade is comfortable, but the second to third becomes hot and muggy; As the monsoon winds begin to recede and with moisture still suspended in the air, the sunlight becomes unbearable due to an increase in the heat index.

Rain

Since Lahore is at the far end of the monsoon coverage area, therefore, the rainfall is less reliable and less in quantity than that of India. Sometimes it rains for three to four days continuously, while at other times, it can rain as a heavy downpour for an hour or two. During the rain, the weather is cool and pleasant; otherwise hot and sensual.

July receives about 8 inches of monsoon rain, August 7 and September about 3 inches. The rainy days in July are from the 8th to the 9th, from the 7th to the 8th of August, while in September they are from the 3rd to the 4th. So we see that both the rains and the rainy days gradually fall towards September.

Sometimes the western disturbance over northern Pakistan interacts with a strong monsoon current already present in Lahore and results in exceptionally heavy rains. That happened from August 22-24, 1996 when 17 inches of rain fell in 72 hours. To fully appreciate just how large this amount is, we looked at the total annual rainfall figure for Lahore. Total annual rainfall in Lahore is 23 inches. It follows, then, that three-quarters of the total annual precipitation was received in those 72 hours.

In short, the weather in Lahore during the monsoon is less hot compared to the months before the monsoon. Most of the total annual precipitation is received through monsoon rains. However, the amount of rain received is highly variable.