We estimate the effect of weather and climate change on postharvest losses using proprietary data on 1.2 million truckloads of processing tomatoes in California. Our reduced-form estimation strategy compares processing tomatoes that originate from the same field in the same growing season but experience different weather and traffic conditions during transit. Hot temperatures during transportation damage product quality and lead to lower producer revenue, particularly if hot temperatures coincide with slow traffic. We predict climate change will increase postharvest losses by century’s end absent additional adaptation. We add to prior work focused on the effects of extreme weather and climate change on farm production with little attention paid to what happens when these products leave the farm gate.