Williams County ND issued the following announcement on March 30.
Beginning next Wednesday, April 6th, the Outdoor Warning System will sound its sirens County-wide on every Wednesday of the month at 12 pm as part of Williams County/Williston Emergency Management 's normal testing procedure.
During peak weather season, which runs from April through October, the sirens are sounded to ensure they are in working order. The test will NOT be conducted if threatening weather is present. During the off-season (October to March), the sirens are only sounded on the first Wednesday of the month.
For more about the Outdoor Warning System, visit https://www.williamsnd.com/outdoor-warning-system/
Original source can be found here.