Soaring maximum temperatures - fanned by a westerly wind pattern and high relative humidity - jacked up the discomfort index in most parts of the state, including Jamshedpur and Dhanbad, on Monday with the average being a punishing 63 degrees, eight notches above normal.
Weathermen said there was no immediate relief in sight unless the skies opened up. A thunderstorm alert has been issued in isolated pockets for the next 48 hours, but it is unlikely to arrest the Celsius stride.
The discomfort index in Jamshedpur was 66 degrees, 11 notches above normal, while in places like Daltonganj, Bokaro and Dhanbad, it oscillated between 65 and 67 degrees. Ranchi, thanks to its relatively low humidity, read a marginal discomfort index of 59 degrees, four notches above normal, while Hazaribagh recorded 61 degrees, six notches above normal.
Places like Chaibasa (in West Singhbhum), Giridih, Koderma, Deoghar, Simdega, Godda and Gumla too recorded a discomfort index above 60 degrees.
According to Met officials, in the pre-monsoon season (April, May and June, till the arrival of monsoon), relative humidity makes the weather oppressive even if temperatures are low.
"A trough extending from Rajasthan to Odisha and an atmospheric circulation over the Bay of Bengal are helping in moisture inflow. This has pushed up the discomfort index. Respite will come only with heavy showers," said an analyst at Patna Meteorological Centre.
Officials at Ranchi Meteorological Centre said the upper-air low-pressure trough - which was stretched between Rajasthan and Odisha, and was crossing MP, Chhattisgarh and Jharkhand - had resulted in light rainfall in a few places like Dhanbad, Bokaro, Giridih and Seraikela on Sunday.
"The trough, located 0.9km above sea level, is gradually becoming weak and there is no possibility of rainfall over Jharkhand unless a sudden change takes place in the system. However, a thunderstorm alert with gusty winds has been issued for the next 48 hours in isolated pockets of the state , especially the northeastern districts such as Dumka, Pakur and Godda," said Upendra Srivastava, a senior meteorologist in Ranchi.
Day temperature witnessed a rise in many places on Monday, but dropped in Daltonganj that had topped the heat chart with around 44°C, three notches above normal, on Sunday.
Noon was uncomfortable in Kolhan too. Reading in the twin Singhbhum districts and Seraikela-Kharsawan hovered around 43°C. The temperature in Jamshedpur was three degrees above normal. The city had been much comfortable at 38.5°C on Sunday. Despite its altitude advantage, Ranchi experienced a hot Monday at around 40°C, two notches above normal. The capital was a tad better at around 39°C a day ago.
