Climate change impact assessments currently ignore the agricultural water use associated with managing extreme weather events. With projected increases in the frequency of exposure to extreme weather events, these footprints can be quite large and cannot be ignored. Through this proposed seed grant, we hope to advance the state-of-the-art of climate change impacts assessment by building research capacity to integrate this critical missing aspect into regional water resources planning considerations. We propose to update the CropSyst cropping systems model to facilitate estimates of irrigation applications for extreme weather management in addition to the current capability to estimate irrigation applications to meet crop evapotranspiration needs. We consider evaporative cooling to control sunburn in apples as an example use case to prototype this model improvement. We also propose to catalog the breadth of crops and contexts where water is used for extreme temperature (high and low) management. Together, these preliminary efforts will allow us to (a) prepare ourselves for a broader regional-scale assessment of the timing and magnitude of agricultural water demands to manage for extreme temperatures and (b) understand how projected changes in these demands might impact instream flows for ecological purposes.