The Fermilab sirens will undergo annual maintenance on Monday, Aug. 1. Testing will begin around 9 a.m. Sirens will be serviced one at a time, and the process will take about one hour to complete. Each service will conclude with a brief sounding of the siren. However, if there is the potential for severe weather later in the day, the sirens will not sound during the maintenance service. Please be aware that the normal monthly siren test will still take place on Tuesday, Aug. 2.