The United Nation’s food agency is warning the world could face a drought-fuelled food crisis of the kind seen in 2007/08.
Food prices surged in July after falling in the previous three months and the UN says they could rise further.
It is particularly worried about the effects of countries restricting exports.
Concern about extreme hot and dry weather in the US Midwest sent corn, more properly known as maize, to a record high last month – up almost 23 percent from June.
Wheat jumped 19 percent – to a four year high – and untimely rains in Brazil meant sugar prices leaped 12 percent.
Meat and dairy prices were little changed in July, but that situation may not last as higher feed costs may prompt farmer to reduce their herds.
The impact will be greatest on the world’s poorest countries , which have to import food as they do not produce enough domestically.
The charity Oxfam said that the surge in grain prices could mean hunger and malnourishment for millions of people around the world.
That is in addition to the nearly one billion who are already too poor to feed themselves.