I think there may be more than one answer to this question. I live and mostly hunt in California.We typically don't have any weather events in the southern central valley. Usually it is dry and HOT. If you research the harvest stats you'll see the results for hunt zones D8, D9, and others are extremely low. I've had better success than most of my friends and I know of others that have had more success than I. Hunting in the mountains around the south central valley is usually a dismal experience, from a harvest perspective. There are places in the areas I hunt that harbor a reasonable amount of deer, but the brush and forest are so thick that it is nearly impossible to find deer during hunting season (temps can be 80-100+ degrees). Considering the temps and the low numbers of animals, I am convinced that the moon phases have a dramatic effect on deer movement.
I drew a tag this year that allowed me to hunt several days later than the regular season. Although the mornings were in the teens some days, the afternoons were typically in the high 60's-70's. We saw deer on on the first part of the hunt and I should have had a shot at a decent buck (stereotypical California hunters...another story for another day...). I had to return to work for a couple of days during the season and when I went back to hunt the following weekend, the moon was full. Areas where we were seeing 20-30 deer/day, I saw nothing but tracks...fresh tracks. It was obvious that the deer were following the same paths and patterns, but it was just earlier in the evenings/mornings, before daylight. This experience is consistent with my hunting deer in California for 40 years
This is typical for my experiences in south central California. I have hunted deer and Elk in Colorado, never experiencing this phenomenon. I don't now if the number of hunt-able deer in Colorado have skewed my observation, but I suspect it may be a part of the equation.
What I do know, is that I will NEVER hunt deer during a full moon in California, ever again!
-Mike