India is launching a $75 million mission using computer models to understand the south-west monsoon and forecast the rains more accurately, officials said. India receives 80% of its annual rainfall during the summer monsoons between June and September. A significant shortfall in rain can trigger drought, which can cause great damage to India's 235 million farmers. There have been reports that this year's monsoons have been less than satisfactory so far, the (BBC) reported. "Understanding the monsoon will be a major priority of the government for the next five years," said Shailesh Nayak, a senior official in the ministry of earth sciences. He said efforts will be made to understand the rains using computer models developed by the UK and the US and gathering fresh data. Forecasting the monsoon is a tricky task, as India's meteorologists have discovered time and again. Last year they predicted a bad monsoon, but in the end the rains turned out to be in excess of what was forecast. The Indian Meteorological Department (IMD) admitted later that it was "not very accurate" in its forecasts. In its 137-year history the IMD has never been able to predict a drought or a flood - the two extremes of a monsoon season - successfully. Experts said scientists all over the world struggle to forecast weather patterns. They say the IMD does a "commendable job, putting its reputation on the block" by making monsoon forecasts every year. The US weather office also struggles to predict droughts for North America but there have been occasions where they have been able to make seasonal drought forecasts, according to experts.