Back when I spoke at BrightonSEO I said after my talk when a question was asked, can you see if your site was affected by looking in the server logs.
My answer at the time was the two sites I had data at that time that I had analysed had seen a spike in Googlebot activity prior to the update, but I did make it clear that 2 sites don’t make something statistically correct.
Over the years since I have analysed a lot more sites and seen that there is no correlation between Googlebot activity and getting hit positive/negative from a penalty.
If you ever get hit either way and wanna send me your logs I am happy to analyse for free.
Anyway I was on holiday for the previous two weeks and say John reply to this tweet and I was I like, F**K it, I am on holiday and not doing server log analysis.
Nothing specific is happening - fluctuations in crawling are pretty normal. I'll double-check, but off-hand there's nothing lined up in that regard.
— 🍌 John 🍌 (@JohnMu) June 7, 2019
Anyway, I got back late yesterday and woke up early today and it still bugged me, what happens if things had changed this time.
I know regularly audit about 20 accounts and have access to their Logs.
Out of the 20, 2 were negatively affected and 3 positive – so again while not a huge sample i took a look at the previous 60 days Google Desktop and Google Mobile Bot activity.
There was nothing significant about any of the sites, in fact, I looked at all 20 in the end, and there were spikes and dips on specific days, but nothing out of the ordinary.
So for now and I can’t see it changing – there is NOT an increase in Google bot activity before an update.
Summary
You will not see a spike in activity before a Google update. However you might see spike or dips for other reasons.