This tabular dataset includes measurements of net radiation, air temperature, relative humidity, wind speed, and calculated reference evapotranspiration (ET0) for a bioretention garden in Douglas County, Nebraska. To determine the amount of water that was lost to the atmosphere, evapotranspiration (ET) was calculated at the Eastern Nebraska Office on Aging (ENOA) bioretention garden by scaling the reference evapotranspiration (ET0) by a landscape coefficient. Measurements of net radiation, air temperature, relative humidity, and wind speed were used to calculate daily ET0 using the Penman-Monteith equation (Monteith and Unsworth, 1990; Allen and others, 1998). Reference evapotranspiration represents ET, in inches, over a well-watered grass of uniform height that completely shades the ground (Allen and others, 1998). To adjust the ET0 to represent the actual ET of the bioretention gardens, a weighted landscape coefficient (KL) was used (Costello and others, 2000).