When I lived in Wisconsin, we blamed the hottest, most sultry days of summer on the corn in Iowa, which was pumping a lot of water vapor into the air. Now there’s a study published in Geophysical Research Letters that takes a scientific look at how the climate in the Corn Belt is changing due to the agriculture there. According to the research, the area of major corn production is cooler and wetter now than it was earlier in the last century when overall ag production was less.  The scientists attribute that in part to transpiration of corn, which puts more water vapor into the air, providing fuel for showers and keeping temperatures lower. It is also due to increases in irrigation in recent decades, which pump additional moisture into the region.

You can read  more about in Science magazine here.

Map of the central United States, showing changes in rainfall during the last third of the 20th century. Areas of increased rainfall are shown in green, with darker colors representing a greater increase.