There have been discernible swings in the rainfall pattern in the state over the past decade or so.
Study of 12-year-old data reveals that almost half the years show a shortfall and the rest, normal/ excess rain.
Though the Met department has predicted good rains this monsoon, especially in the next few days, the rainfall till today continues to be minus 4 per cent less than normal, with Anantapur, Nalgo-nda, Visakhapatnam and Nizamabad getting an insufficient amount of rainfall.
The normal annual rainfall in the state is 940 mm. Plus 19 per cent and minus 9 per cent rainfall is considered normal.
From June 1 till Friday, the total average rainfall in the state this monsoon has been minus 4 per cent — 300.3 mm, as against the norm of 311.6 mm.
According to Met, irrigation and agriculture depa-rtment sources, agriculture in AP is centered around rainfall and production of food grains is dependent on seasonal distribution of rain.
The South West monsoon accounts for 66 per cent of the rainfall from June to September while North West monsoon accounts for 24 per cent of rainfall received from October to December.
But there is a wide variation in the distribution of raif-all, ranging from less than 600 mm to over 1200 mm.
The variation of rainfall from one year to another is also very high, apparent from the rainfall data.