Sorry, I think what I was confusing was the autocorrelation given by the CORREL function to the calculated autocorrelation, corrected for the degrees of freedom. I wasn't using the CORREL function, but my code was doing the same thing.
I'm trying to follow the steps outlined here, http://www.neas-seminars.com/discussions/download.aspx?id=2133&MessageID=7747
about finding the autocorrelations, Box-Pierce Q, etc, and it all seems to work fine, BUT, it's still giving me a Box-Pierce Q-statistic for 50 lags of 4,569.472. Does this just say that my de-seasonalized temperatures are NOT a white noise process, and that they follow some sort of ARIMA process?