The extra sunshine I would not blame at all. I have worked in my gardens daily for hours all summer and had my D3 measure at 64ng in August!!! Then, by September 21st, I was back in cycle. At that point, I went on the D3 year round. And have not had a full cycle since! Until then, I thought that my gardening provided enough D to get through the summer in a better range for a CHer, say above 80ng. Nope. It did not.
I highly recommend the D3 Regimen! Easy, good for you and cheap compared to Pharma.