What does this となった express?


For full context, see
[here](https://www3.nhk.or.jp/news/html/20180125/k10011302761000.html).

The sentence in question:

> 厳しい冷え込み **となった** ２５日朝、滝つぼが一面凍りついた **ほか**
> 、流れ落ちる滝の周りにはつららができていて、岩場が氷で白く染まっていました。

I already posted a fairly similar question
[here](https://japanese.stackexchange.com/questions/56250/what-does-
this-%e3%81%a8-do?noredirect=1#comment97449_56250).

But I cant really find out how to apply the regularities lined out in the
answers can be applied to なる here.  
So basically, I dont know how と in 厳しい冷え込み **と** なった２５日朝 is used here. I also
don't really know what to do with ほか in 滝つぼが一面凍りついた **ほか**.

My attempt at translation:

> "There was intense cooldown on the 25th morning, and one side of the
> waterfall basin froze over (ほか???) and concerning in the surroundings of the
> waterfall, there appeared icicles and the rocky area was dyed white."

To make this translation, I just jused "and" constructions to cover the parts
I didnt understand, but I would definitely like to know how these parts work
^^




I'd like to answer just the question about ほか. I assume you're familiar with
the clause-initial phrase/word そのほか, meaning "aside from/in addition to
that..." (If not, here are [examples on
Jisho](http://jisho.org/search/%E3%81%9D%E3%81%AE%E3%81%BB%E3%81%8B%E3%80%80%23sentences).)

The usage in your example in the same, except that the pronoun その is replaced
by a concrete phrase. In short, Aほか、B means "Aside from A, B." This can be a
disjunctive meaning ("Aside from the fire, it was a great party.") but it
doesn't have to be, and it this case it isn't.




I'd like to answer just the question about ほか. I assume you're familiar with
the clause-initial phrase/word そのほか, meaning "aside from/in addition to
that..." (If not, here are [examples on
Jisho](http://jisho.org/search/%E3%81%9D%E3%81%AE%E3%81%BB%E3%81%8B%E3%80%80%23sentences).)

The usage in your example in the same, except that the pronoun その is replaced
by a concrete phrase. In short, Aほか、B means "Aside from A, B." This can be a
disjunctive meaning ("Aside from the fire, it was a great party.") but it
doesn't have to be, and it this case it isn't.

