Meaning of "bareback"

I've been watching Guy Maddin's 2007 My Winnipeg and there's a sentence there I have difficulty understanding. The narrator is talking about the coldest month, January, and it goes something like this:

The deepest part of the winter. No end in sight. The condoms come off. These are the bareback months of Winnipeg. Your breath freezes in front of your face and falls to your feet with a tinkle.

I assume the first sentence refers to the idea that when it's cold penises tend to "shrink" (or is it just me?). But what does the "bareback month" mean here?

The phrase in question definitely have a sexual connotation. But not for vulgarity’s sake.

Bareback can refer to riding any animal without some covering or apparatus between it and the rider. But, it also, generically, means having ones back exposed or uncovered. A woman wearing a backless dress in an environment where it would not be appropriate could be considered barebacked. However, in the context of the statement in the question, it definitely means sex without a condom. Something that is considered risky.

During the extremely cold months in the US and Canada. People tend to stay inside their own homes more so than other months. With little else to do, couples find ways to entertain themselves and each other. And, since there is more time spent in close proximity, intimacy becomes the norm. Anecdotally, there is a rise in the birth rate nine months later (around the month of October, in this case).

Some people are half-facetiously predicting an increase in the birth rate for the year 2021 due to the COVID-19 pandemic. This particular author might call 2020 the bareback year.