My experience so far playing in the gazebo has included:
overhead cover is relatively easy to arrange, but wind is the enemy
if you have a slatted table, some sort of mat is necessary, perhaps weighted at the corners
generally a single card, chit, etc. will stay where it’s put, but stacks may start to slide
I’ve played Aeon’s End (the gems look great in the sunlight), Dead of Winter, RoboRally, VOLT, Project L, Ghost Stories, NMBR 9, Rallman GT, Modern Art and Tiny Towns.
I think Deep Sea Adventures would probably work, since all the components are fairly solid. Maybe not if it’s windy but on an average day you’d be fine. Railroad Ink is a great outdoors game since players can hold onto their own boards which just leaves the dice. Everything is plastic and harder to ruin as well. Hive, full size or pocket edition, is a great recommendation from above.
And I expect Chess is the most common outside-game, so if that’s your thing I think it fits.
If there’s not enough wind to blow away thick card, then Skull, Ice Team, and Hey, That’s My Fish will all work fine.
Kung Fu Zoo would work great, as long as no one’s too enthusiastic and flicks a die into someone else’s garden. (I was just looking at my collection, but other dexterity games like Flick 'em Up and Men at Work would work well too, right?).
Swap out the cheques for poker chips and The Estates would be perfect. Oh, and you’d need something to replace the cards that indicate who owns what company. Maybe some coloured cubes or meeples …
Mafia de Cuba wouldn’t need any changes. You don’t even need a table!
And, if you have something to weigh down the reference cards (which is fine as they don’t need to be moved at all), Dice Masters (and I assume Quarriors that it’s based on?) is the perfect covid-safe game! Easy to play 6’ apart and nothing gets exchanged between players.
I can’t help but look at some of the suggestions and wonder if people live in some windless wonderland that exists somewhere. I think the only game I’ve played to date which works well outside is Wavelength, because the main component is heavy plastic and the cards live in a sheltered slot.
Sadly, no. Unless you’re playing oversized Jenga, stacking games are ruined by wind.
It’s old (classic?), but rummikub was always a go to at family reunion picnics. All the pieces are chunky and water-proof. They just need to stay semi-flat. Only potential problem is if you’re playing a “real” game keeping score over multiple rounds, someone has to keep track of a piece of paper. Qwirkle probably fits in the same general category.