Changes in Climate and Estimated Evaporation Across a Large Irrigated Area in Idaho

G round level climatic measurements were taken along a 50 km transect going from dry sagebrush land into the center of a large irrigated area in southern Idaho. Measurements in May, when the desert area was dry, indicated that climatic changes across the transect were minimal. In August, when the desert was obviously very dry, air temperatures decreased, vapor pressure increased, and windspeed was reduced about 40 percent within the irrigated area. The results demonstrate that any weather service agency or group must consider the distance from dry surroundings when selecting sites that are to be representative of climatic conditions over irrigated fields.