The Field Systems Operations Center (FSOC) ASOS Dataset Library is a dynamic collection of raw sensor data that has been collected from various ASOS sites and formatted for use by the ASOS simulator: ASENSE. The purpose of the FSOC ASOS Dataset Library is to thoroughly test ASOS firmware and algorithm improvements, with particular attention being paid to scenarios which stress ASOS algorithms. The FSOC ASOS Dataset Library is organized into cases based on a cadre of meteorological events ranging from clear skies to severe winter storms. Cases generally range in duration from 2 to 8 hours; however there are cases of shorter and longer duration. Each case is made up of a collection of datasets from one or more ASOS sensors. Cases contain 1 to 15 datasets, observations collected from the ASOS for the event, test scenarios and expected results based on the present software baseline. To date, about 80 cases are contained in the library, with more cases being added as they occur.