Temperature changes causing internet to drop

I’ve been dealing with this issue on and off for 2+ years now. When ever the temperature changes or as it gets warmer during the day, my internet will drop. My current downstream signal is high (around 😎 in the morning. Around 12 or 1 that signal will fluctuate as far down as 1 or 2 causing the internet connection to disconnect. The line from the pole to my home is less than 6 mos old and the connection from the box to the modem is brand new. I am at the end of the line on my block so clearly there is an issue with the line further up the street. How do I get this fixed.