I hear ya. I can't believe it's below 100 in Houston.
I've found that all my best shooting bamboo shafts are way smaller in diameter. Like 8 mm. I started making them from larger diameters, like 10mm and a little bigger, and they flew horrible from my 55lbs osage. It could have been any number of things I was doing different to cause the bad flight, but the best ones I have that all shoot tight groups are thin.
The only thing you can do it finish and try them.