Where should I pregame?
Obviously it depends on which display we're talking about. If you're headed to Tacoma, just pick one of the beer gardens and stay there. All day. If you're in Kirkland, our advice is to play a couple of rounds at Flatstick Pub, or post-up on the patio at Cactus (or both) until the sun sets, then head across the street to Marina Park for the show. In Bellevue, we suggest Jason Willson's speakeasy inspired Civility Unrest in the new(ish) Lincoln Square Expansion kitty corner from the park, or one of the bars (Monsoon!) just to South on Main St.
In Seattle you're better off trying a lakefront bar like Westward, which thanks to its excellent food and man-made beach out front is probably the best restaurant/bar on the shores of Lake Union, and probably the best choice if you're looking for a place to watch the fireworks. But unless you're one of the lucky few to score a ticket to their sold out holiday party, you better pick someplace else, like Chandler's Crabhouse on the Southern shore, or White Swan Public House off Fairview, in the space that used to be A Terrible Beauty, and BluWater Bistro, and… well, you get it. Other Seattle options include Thrillist favorite The Lookout on Capitol Hill, or Keira Knightley's favorite Seattle bar Little Water Cantina (she was spotted here whilst filming a movie a few years ago), which actually takes reservations (for free), but only for large groups.
Of course you don't have to worry about any of that if you've got a boat. Or, even better, if one of your friends' does. Or, you know, buying a boat. If those things aren’t an option there are several booze cruises, including waterways cruises, and Seattle Boat Parties that can hook you up.
What will the weather be like?
It should be excellent! Looking like sunshine and temperatures in the mid '70s. Obviously, it can get cold on the beach at night -- especially in Tacoma where the display is on the shores of Puget Sound, rather than on a lake -- but at least we don't have to worry about watching fireworks in the rain. Or worry that much, anyway.