The heatwave in the United States may help bolster international commodity prices for beef and dairy farmers in New Zealand.
Official updates show the yields on the US's corn crop have deteriorated further, with only 40% of the crop in good or excellent condition by last Sunday, compared with 69% at the same time last year.
ANZ New Zealand rurals economist Con Williams says the crop is in the critical first kernel growth stage, known as silking, which is critical to yields, and it needs water soon.
Mr Williams says that means higher production costs, which should eventually reverse flagging commodity prices.
He says the impact of the drought in the US is likely to influence prices early next year, rather than this year.