Weather Extremes That Affect Various Agricultural Commodities

Broad-scale weather extremes that have impacts on yield are tabulated for several agricultural commodities organized into 13 groupings. How these weather metrics cause harm is also discussed briefly in the context of each commodity. Cultivars have differing properties, so most thresholds are somewhat imprecise, though threshold temperatures near freezing and near 35–40°C are common. Timing is critical to the impact of an extreme and the most critical time for crops extends from just before flowering until the next one to two months. Sometimes the extreme does not cause the impact but sets in motion physiological changes making the plant vulnerable to near normal weather later. Beyond mortality and morbidity thresholds, combinations of atmospheric variables are important, such as high humidity with high temperatures.