Decide on the call window
Pick a time on the wedding day. Usually 4–6 hours before ceremony. When you'll commit to the call. Past that window, you keep the original plan and trust it.
Have a paired indoor or covered configuration
The backup shouldn't be an apology. The strongest backup plans are designed at the same time as the original setup, with the same care for sightlines and light.
Coordinate the call with one person
Either your planner or the venue's coordinator should own the call. Couples shouldn't be checking radar at noon on their wedding day.
Communicate the change to guests calmly
A short, warm note from the wedding party (or planner) keeps guests calm. No scrambling at the door.