Several things can cause higher than normal CPU Temperature after a certain amount of time has passed.
1- The thermal paste on the CPU Cooler might have dried out or lost its efficiency after a year. So I would apply new Thermal paste making sure all the old thermal paste was removed using 90% or higher Isopropyl Alcohol.
2- Dirty Air CPU Cooler Heat sink. Make sure the CPU Cooler heat sink is clean of dust and dirt.
3- CPU Cooler fan not running as well as before or you need to create a more aggressive CPU Cooler fan profile where it will go to maximum speed at a lower CPU temperature.
4- Poor air circulation inside your PC case. Remove the side panel and see if your average CPU temps are slightly cooler than before.
5- Clean out your PC Case air filters and screens. If dirty that can cause poor air circulation.
6- Make sure all of your PC Case fans are working. If one has gone bad that can cause poor air circulation in your PC case.
7- Make sure your PSU is outputting proper voltages to your Motherboard and hardware.
8- Your ambient Room temperature is hotter than normal. Hot rooms will circulate hot air inside your PC case.