For El Nino, yes quasi periodicity seems apparent in a cursory look at the data. But if data really does have a fundamental period, even though that data might be noisy, then an FFT analysis will show that period. FFT of El Nino is notorious for not producing anything sensible.

Often times one learns most about data simply by counting.





For the Salem - Eugene comparison, there is obviously a calibration problem.



For winter time precipitation, notice the change in Eugene; this is, in effect, the principal component of climate change in our local region - it precpitates much less and has much less variance in recent years.