Use of particle や with も


I was reading a textbook and found this sentence:

> 海や山もあれるそうです。

I don't understand what the や is doing there with も.

The full piece where it comes from is:

> あさっての夕方ごろからくずれるそうです。気温も下がるそうです。海や山もあれるそうです。

And the person was answering to a question about weather forecasts.

Is that supposed to mean something like "Both the sea and the mountain..." or
is it just a typo?




> あさっての夕方ごろからくずれるそうです。気温 **も** 下がるそうです。海 **や** 山 **も** あれるそうです。

It's using 山 **も** to say "Adding to / Beside くずれる(=雨が降る/it will rain) and
気温が下がる(temperature will drop), 海や山 will _also_ be rough."

The も in 気温 **も** is being used in the same way: "Adding to / Beside くずれる(the
rain), the temperature will drop, _too_."

The や implies that places/areas other than 海と山 will also be rough. Compare:

> 海と山が荒れる -- (Just) The sea and mountains will be rough.  
>  海と山 **も** 荒れる -- Also, the sea and mountains will be rough.  
>  海 **も** 山 **も** 荒れる -- (Also,) Both the sea and mountains will be rough.  
>  海 **や** 山が荒れる -- The sea and mountains and other places will be rough.  
>  海 **や** 山 **も** 荒れる -- Also, the sea and mountains and other places will be
> rough.




> あさっての夕方ごろからくずれるそうです。気温 **も** 下がるそうです。海 **や** 山 **も** あれるそうです。

It's using 山 **も** to say "Adding to / Beside くずれる(=雨が降る/it will rain) and
気温が下がる(temperature will drop), 海や山 will _also_ be rough."

The も in 気温 **も** is being used in the same way: "Adding to / Beside くずれる(the
rain), the temperature will drop, _too_."

The や implies that places/areas other than 海と山 will also be rough. Compare:

> 海と山が荒れる -- (Just) The sea and mountains will be rough.  
>  海と山 **も** 荒れる -- Also, the sea and mountains will be rough.  
>  海 **も** 山 **も** 荒れる -- (Also,) Both the sea and mountains will be rough.  
>  海 **や** 山が荒れる -- The sea and mountains and other places will be rough.  
>  海 **や** 山 **も** 荒れる -- Also, the sea and mountains and other places will be
> rough.

