In the week to Friday (June 22) UK July feed wheat futures closed £8/t higher at £183/t - a 12-month high, according to the Market Report from the Home-Grown Cereals Authority (HGCA).
Global weather conditions continue to underpin grain markets, says the HGCA.
The US Midwest continues to suffer from drought and has seen temperatures rise to record-breaking levels in some areas.
Hot and dry conditions in the US led to the United States Department for Agriculture to downgrade forecasts for the soyabean and maize harvests. More dry weather is forecast at a time when some maize crops are reaching pollination.
Drought
The US government announced recently that crop growing conditions were the worst it has since 1988, when US grain production was cut by 30% due to drought.
US farmers planted higher levels of crops this year. But the drought has scuppered hopes for a boost to supplies this year.
America is not the only part of the world where crop production is being hit by sustained hot weather. Farmers from the Black Sea and the North China Plain are also suffering from a prolonged dry spell.
Meanwhile, production in Ukraine could be 8% lower after dry weather in June.
These factors are creating unease as pressure builds on global food stores that are nearing record lows.