NOAA and NASA temperature graphs aren’t useful for science, because the data has been altered.
Climate at a Glance | Statewide Time Series | National Centers for Environmental Information (NCEI)
In order to do legitimate science, it is necessary to work with legitimate data.
I ran the Tennessee 365 day mean temperatures though Fourier Transform and found cyclical behavior at intervals of 3, 4, 5, 9, 11, 18 and 32 years.
Each official temperature series is better described as Manntasy rather than actual data.