A severe heat wave sweeping across the country, with temperatures of almost 44 C, has killed at least 80 people so far, officials said on Sunday.

Majority of deaths were reported in Orissa. A state government official said they were investigating reports of 53 deaths from various parts of the state. "District collectors have been asked to investigate and submit reports on other deaths," said Mr Bhimsen Gochhayat. Orissa has decided to shut down schools from next Tuesday, advancing the annual summer holiday.

Other deaths were reported from Uttar Pradesh and Madhya Pradesh. New Delhi recorded a maximum temperature of 43.7 degrees Celsius on Saturday, presaging a hot summer in the next two months in the nation's capital and other parts of northern and eastern India.

The highest temperature in the past 24 hours was 47 C at Ganganagar, in Rajasthan. Summer temperatures have been 4-6 degrees Celsius above normal over most parts of northern and central India since March, weather officials said.

Weather officials say with summer temperatures set to remain above average , there were hopes of heavy rains at the start of the monsoon season that will help early sowing of rice, soybeans and lentils. A senior weather official said he was expecting temperatures to come down a bit next week, bringing some relief in hilly areas, which could experience light rain.

The scorching weather, which officials say would continue over northern , northwestern and central India in the next 48 hours, also may have some impact on wheat production, exporters and flour-mill associations said.This year, the country is expected to produce about 82 million tonnes of wheat in 2009/10, but there could be a shortage of 1-1 .5 million tonnes due to the heatwave, said, the Roller Flour Millers Federation of India secretary general Veena Sharma.

"Most of the harvesting is over, but there definitely will be a slight shortage of 1-1 .5 million tonnes due to the extreme weather conditions,"

India is relying on a bumper wheat crop to make up for a 14.2% drop in rice output, the major summer-sown grain, marred by the worst monsoon in 37 years last year. "The time it (wheat) normally takes to get ripe has been shortened and as a result the size of the grain could be smaller with a marginal effect on production," All-India Grain Exporters Association president D P Singh said.