I’m assuming you are referring to the upper part of the river. From the Derby Dam to Long Island Sound the river is considered tidal so the marine regulations apply there which for the most part means no closed season.

For Lake Zoar and Lake Lillinonah the statewide regulations apply even though technically the lakes are part of the Housatonic River which means for the most part they are open year round. The only exception being trout from which can only be taken from the 3rd Saturday in April to the end of February. Lake Housatonic is a Bass management lake so there are creel limits on bass different from the statewide regulation. Normally you can keep 6 fish of 12 inches or more however in Lake Housatonic the creel limit is 2 fish with a 16 inch minimum. The closed season for trout applies on Lake Housatonic also.

For the upper river above the Bleachery Dam in New Milford, Thermal refuges are any areas within 100 feet of the mouths of the Kent Falls Brook and Macedonia Brook and are closed to fishing from June 15 to August 31. If additional refuge areas are identified by fisheries and closed, the area will be posted.

We then have the Housatonic River TMA that runs from Rt 112 & Rt 7 in Salisbury/Canaan south to the bridge at Rt 4 & 7 in Cornwall/Sharon. That TMA is open year round except for the refuge areas. The TMA is catch and release only for trout and there is a fly fishing only area in the 3 mile section of the TMA from the Rt 4 bridge in Cornwall/Salisbury going north. Those areas are posted.

There are a couple Bass management areas further south on the river.

There is the Stanley Tract BMA that runs from Dawn Hill Rd in Sharon to Skiff Mountain Rd in Kent. The statewide regulations apply there so it’s open year round with a creel limit of 6 fish with no minimum size requirement.

The Bulls Bridge TMA/BMA runs from the Bulls Bridge Dam in Kent south to the Gaylordsville bridge where Rt 7 crosses the river. It also includes the Ten Mile River from the NY line to where it merges with the Housatonic. That area is open year round except within 100 feet of the refuge areas that are posted from June 15 to August 31st. Trout and bass are catch and release only in the TMA/BMA.