This research project analyzed 21 years of historical weather data from the Oklahoma Mesonet system.  The data examined the practicality of flying unmanned aircraft for various agricultural purposes in Oklahoma.  Fixed-wing and rotary wing (quad copter, octocopter) flight parameters were determined and their performance envelope was verified as a function of weather conditions.  The project explored Oklahoma’s Mesonet data in order to find days that are acceptable for flying unmanned aircraft and determining specific time periods which meet criteria for varying degrees of accuracy.  Since Oklahoma has great regional variability in weather and crops, the flight recommendations were assigned to specific Mesonet sites.  The results of this work will help define optimum dates of flight for specific crop issues and determine which Mesonet sites to utilize for those crops.  Weather data studied included wind speed and direction, cloud cover, relative humidity, precipitation, and solar radiation.  Varying levels of UAV/sensor performance based on data requirements (i.e., pretty pictures, relative NDVI, geo-rectified radiometric imagery, research-grade data) were considered when establishing flyable weather criteria.