Ranchi: Jharkhand won't be stood up by the rains this year. Weathermen have, for once, confidently forecast timely advent of the southwest monsoon.

"The conditions are completely favourable for the advancement of the monsoon currents. The rains will hit south Arabian sea by May-end. If that happens, monsoon will arrive in Jharkhand on June 15," said a climate analyst at the IMD's Patna centre.

Pre-monsoon rain has already been handsome this time. Chaibasa in West Singhbhum, with 257.9mm of cumulative rainfall from March till May 22, topped the chart. This is followed by 249.5mm recorded by the IMD observatory in Jamshedpur while Ranchi registered cumulative rainfall of 102.9mm. In May alone, the capital has recorded around 62mm and the steel city 50mm.

Met officials confirmed that never before in the last 10 years or so had Jamshedpur and Chaibasa, which fall in southern Jharkhand, recorded such impressive rainfall in pre-monsoon months.

A peak summer month, May this year has mostly stayed cooler than usual, thanks to frequent bouts of thunderstorm and showers caused by cyclonic circulations and low-pressure troughs.

In Met parlance, a heat wave condition is declared when the maximum temperature in a particular region climbs five notches above the average normal. Mercury in May, so far, has not touched the oppressive 40°C mark on most days in several places, including Ranchi and Jamshedpur. A heat wave has remained conspicuous by its absence.

According to Met data, day temperatures have been hovering between 35°C and 38°C in most parts of the state during the past week. Last May, maximum readings had reached 44°C in several places.

Thursday's forecast said Daltonganj's day temperature was likely to be around 43°C in the next 24 hours, an exception this summer, possibly as the region is going dry for a few days. Maximum readings in Ranchi, Jamshedpur and several other places in southern and north-eastern parts of the state are expected to hover between 36 and 38 degrees in the next few days owing to a trough running from east Rajasthan to Gangetic Bengal across Jharkhand.

"Isolated rain and thunderstorm activity will continue till May 26 and this will help in keeping the day temperatures below 40°C in most parts of the state, including Ranchi and Jamshedpur," Upendra Srivastava, a senior official at Ranchi Met centre, said.