There are many things to do in Seattle in summer. You should expect (typically) warm, dry, sunny days in late July with cool nights. Daytime temperatures often start out cool and hit the 80's from 1pm to 6pm or 7pm. Evenings can be breezy and cool when the sun sets, so bringing a sweater is a good idea. Some activities to consider are:

-Explore Pike Place Market (at 1st and Pike). It is quite large and gets crowded in the middle of the day. Part of it is inside, and part is open air.

-Take a Ferry to Bainbridge Island (from the Ferry Terminal at Alaskan Way and Madison Street). You can walk around Winslow on the other side, or just take the ferry back for some time on the Puget Sound.

-Visit the Ballard Locks (near the wedding venue in Ballard) to see Salmon coming through the Fish Ladders (on the south side facing Queen Anne Hill). It is also interesting to watch the locks take the boats from the lower saltwater side to the somewhat higher fresh water chain of lakes and passages.

-Rent a Kayak on Lake Union. Lake Union is just north of the Seattle downtown, past quite a few Amazon offices. You can rent kayaks in the southeast corner of the lake at Moss Bay (https://www.mossbay.co/) or on the west side of the lake at the Northwest Outdoor Center (https://www.nwoc.com/). Just keep your eyes peeled for float planes taking off and landing on the lake as you paddle around. There are houseboats (as in Sleepless in Seattle) to paddle past.

-Take a Scenic Float Plane Ride. Speaking of those float planes, Kenmore Air on Lake Union offers scenic float plane tours. Check https://kenmoreair.com/seattle-scenic/

-Attend a Mariners game - just south of downtown on 1st Ave at T-Mobile Park. It is walking distance.

-Attend the Bite of Seattle Festival in Seattle Center near the Space Needle. It is an annual food festival that runs Friday, Saturday, and Sunday of that weekend. More info at https://biteofseattle.com/

-Attend the Timber Outdoor Music Festival: It runs Friday to Sunday in Carnation, about 45 minutes drive northeast of Seattle in the foothills. Info is here: https://timbermusicfest.com/

- Find Live Music. This Calendar has some random and varied live music: https://everout.com/seattle/events/?category=live-music&start-date=2025-07-25. You can typically find music at clubs near Pioneer Square or at venues like the Tractor Tavern (near the wedding venue - see https://tractortavern.com/calendar/) or Showbox family of venues (https://www.showboxpresents.com/events/all). Also, for Country fans, Morgan Wallen is playing Friday and Saturday at 5:30pm at Lumen Field (Seahawks stadium) with Miranda Lambert and Brooks & Dunn. Meanwhile, DEVO is playing July 23 and 24 at the Woodland Park Zoo in Seattle, which is a fun outdoor location. See https://everout.com/seattle/events/devo/e198252/.