Although we don't get severe weather up here all that often, most of the sirens up here are for VFD use, and most town do a daily blast at either noon or 6pm, or both. There are a few towns that use their sirens for non VFD use. Here's a few that I know of that regularly test
Vernon: current system: WS 2008, 3T22, single toned 2, 12 port 5 (2), future system: 7 various WS 2000s, 1st Saturday of the month for 3 minutes in 4 long cycles of attack (20 seconds on 10 off) on the mechanical sirens, wail on the 2008. A brief 1050hz tone followed by a live test message is given over the 2008 just before the test starts. The sirens are not used for VFD use
Glastonbury: 2 2740s, 2 2902s, 1st Saturday of the month at 11am for 1 minute in I assume alert, and in January and July a brief test announcment just before th etest starts. Also one blast daily at noon (not sure if they still do, I'll have to check on that), and 3 rounds of wail for fire calls between 7AM and 7PM
Wolcott: single toned 2, 5T (2), WS 2016 (3), SD-10 (2), 1st saturday of the month at noon for 20 seconds. They also use the 2 and 5Ts for fire calls
Millstone Nuclear power plant, various towns with in a 10 mile radious of the plant: a rapidly disapearing system of various WS 2000s (we have 8 of them counting the 2008) formerly totaling 125 sirens. Upgrading in progress, to 81 2910s. Testing varies, but from what I've heard the plant tests on the 1st Wednesday of the month at 11am, in alert for 3 minutes, and attack for an unknown time, possibily 3 minutes. A test message is given jusr before the test. Some towns also uses the WS 2000s for VFD use, and usualy do a test blast daily at noon, and wail for fire calls. The Niantic Men's prison also uses a few of the WS 2000s for prison escapes, using hi-lo, I assume they test that signal from time to time.