A book I use for so much inspiration and data is by my Bigfoot Researcher hero John Green:
The Best of Sasquatch Bigfoot from Amazon.com
I have to call out credit right away because I used data directly from the book to build a graph of when during the year Bigfoot sightings seem to occur most often.

This is from John’s database at the time, the blue bars are number of sightings he recorded for that month over the years. July and Aug make sense as people are out in the bush the most in the summer and would have more encounters. But does it really make sense? What about the seasonal workers? What about the fact the in the Pacific Northwest we have a temperate climate? Or is this because more people are out then or cause of him? Another thing John mentions is that where there is greater than 20 inches of rain per year, Bigfoot is there. The temperate climate I mentioned fits with that.
And what’s with that spike in October? Halloween? And April? April Fool’s Day? May makes sense, cause it’s so dam wet around here in May.
So I haven’t really reached any conclusions here, just more questions. I’ll just focus my efforts on the Summer and Fall and see what I find.