The standard joke is that VCs take the entire summer off. It isn’t true, but there is a good reason for the myth: it’s almost impossible to close a funding round over the summer.
The reason for this is quite simple, most deals require consensus of the partnership, and while no individual partner takes the entire summer off, at any time at least one decision maker is out of town with their kids. Or off on the Playa for Burning Man.
This means that the longer or more complex a funding is, the less likely it will happen over the summer. Raising a seed round from a single micro VC? Sure, that is likely to get done. I even know of one micro VC that loves to close summer deals since they’re “the only game in town.” But if you’re raising a $50M Series C from a new lead that includes follow on investments by two other VCS? That’s probably not happening until after Labor Day!
If you need sign off from multiple investors, plan ahead so that you aren’t caught in the situation where there is always someone out of town.