Take into account seasonal temperature variations which can affect behaviors of the mod, such as frost breath and playing of certain biome sounds.

Tested with the Legacy pack (which has Fabric Seasons) and it looks like the temperature that DS is using is affected by their seasons. With the next update it should work as it.

It varies. In my rule set for various effects there is a check for whether water can freeze. Of course, this is based on temperature. In terms of the easiest to experience right away is the frost breath effect. Another easy one to spot is the firefly effect - they will not show if it's too cold.

EDIT: For the 1.20.4 version of Dynamic Surroundings w/Serene Seasons if the clock overlay is enabled the current season will be displayed along with time information. Fabric Seasons does not exist for MC 1.20.4. Once it does I can add support for displaying the current season.

Some players use both though there is overlap with what the mods are trying to achieve. I don't run with both because it's too much sound load for me. Give it a try.

could this be added to fabric seasons?

They don't have a declared API set. I would need something more formal that would allow me to get temperature and precipitation for a biome at a given block position. Once they add that then I can provide support. I don't want to hack around it because then it becomes fragile.

Pushed update to CurseForge and Modrinth.