If the shortage of rainfall lasts until early July, the North's crop production could decline by as much as 20 percent from last year, the South's Unification Ministry said.
North Korea has suffered regular chronic food shortages -- hundreds of thousands are believed to have died during a famine in the mid- to late-1990s -- with the situation exacerbated by floods, droughts and mismanagement.
UN figures show up to 70 per cent of the country remains food insecure and 28 per cent of children under the age of five are stunted.
Kim Jong-Un, who became leader after the death of his father, Kim Jong-Il, in December 2011, allowed farmers to keep 30 per cent of their production quota, plus any excess. Last year their portion was raised to 60 per cent, the ministry said.
But the prospects for this year are distinctly gloomy, given a prolonged drought and lack of fertiliser, the ministry said.
In May, precipitation across North Korea reached 56.7 per cent of the average rainfall recorded between 1981 and 2010.
