Summer wind enhances potential evapotranspiration in the Great Plains by a large but predictable amount. This high potential evaporation can be reduced by lowering windspeeds with windbreaks or barriers. Windbreaks reduce evaporation rates from a wet surface proportionably to windspeed reduction with a proportionality constant usually less than 0.5. Use of windbreaks for reducing windspeed causes other changes in the microclimate. The highest humidity and humidity gradients, highest daytime air temperature, lowest nighttime air temperature, and generally the steepest temperature gradients all occurred in the areas where the windbreak reduced windspeed to the lowest level. The absolute humidity was lower at 12 times the windbreaks height leeward than in the open field. These findings indicate that windbreaks lower the evaporative demand and induce a more favorable environment for plant growth in the harsh climate of the Great Plains. However, additional research is needed to evaluate plant response and actual evaporation as influenced by barrier induced microclimate. (WRSIC abstract).