Rain in cities across upper Pakistan broke the heatwave on Wednesday, the second day of Eid.

It rained in Dera Murad Jamali, Loralai, Bahawalnagar, Khanpur and Jhelum. The Met Office had predicted dust thunderstorms over the Eid holidays from May 1 to 5.

Karachi is expected to see a maximum of 33 degrees centigrade and in the upper 20s for the rest of the week.

The rain broke the heatwave effect that the country suffered in April, leading into May. This year the severity was record-breaking. "This is the first time in decades that Pakistan is experiencing what many call a 'spring-less year," Minister of Climate Change, Sherry Rehman said.

Pakistan and India are experiencing excessive #heat.

To avoid more and more people suffering from climate disasters, we must

? increase investments in adaptation
? halve emissions by 2030

Dataviz by @ScottDuncanWX pic.twitter.com/Ax9XqRMaU5

— UN Climate Change (@UNFCCC) April 28, 2022

The PMD said that La Niña conditions are likely to continue with weak intensity during May 2022. This means it will rain less across Pakistan. Day temperatures are likely to be above normal all over the country. This dryer period may increase water demand for standing crops and vegetables. Higher temperatures will increase snowmelt in the Northern Areas which could reduce water stress caused by low rainfall.

On May 1, the temperature climbed to 121.1°F (49.5°C) in Nawabshah, which is likely the hottest temperature on record in the Northern Hemisphere so far this year. Jacobabad hit an unbearable 120.2F (49.0°C) on April 30.

Today 2 May the max. temperature in Pakistan was 47.0C at Sibbi. After few cooler days,the extreme heat will come back worse than ever by the next weekend with expected max. temperatures near and later next week even above 50C for the following >10 days. Follow the updates. pic.twitter.com/4Y50DsoQKh

— Extreme Temperatures Around The World (@extremetemps) May 2, 2022

A satellite operating under the European Space Agency that collects land surface temperature showed that on April 29, 2022 the land surface temperature crossed 62°C/143°F. Land surface temperature is different from air temperature. Land surface temperature is the heat that radiates up from the ground. Air temperature is the heat in the air we feel. You can understand this difference in temperatures by thinking of how hot a road feels, compared to a patch of grass and the air above it on a hot day.

The current extreme #heatwave in #Pakistan and #India as seen today, on the fourth intense hot day, by #Copernicus #Sentinel3 LST (Land Surface Temperature, not Air!). LST collected on April 29 shows max value exceeding 62°C/143°F. Gaps due to cloud/snow/nodata. #ClimateEmergency pic.twitter.com/0MCMkcSg0t

— ADAM Platform (@PlatformAdam) April 29, 2022

Scientists caution though that there are different ways to measure heat. Land surface temperature is just one of them. (Other ways are the humidity-measuring Wet Bulb Temperature).

Heatwaves happen when air is trapped in an area for a longer time. This causes the temperature to go up. This happens because high-pressure air circulation systems prevent the air near the ground from rising. The warm air is trapped. Extra humidity does not help. Scientists believe that heatwaves are caused mostly because of how human beings change their environment, for example, with more building construction.