Weather contingencies are easiest when the indoor option is treated as a second real layout. The goal is not to predict the forecast months ahead; it is to make the eventual decision straightforward.
Draw both versions
Measure the outdoor and indoor spaces separately. Sketch where the ceremony focal point, chairs, aisle and welcome elements go in each. The indoor room may have lower ceilings, different sightlines or less space for the same backdrop.
Mark what stays, moves or disappears in the alternate layout. A grounded arrangement may transfer easily; a large frame or loose petal path may not. Do not pay for an element whose only possible home is a weather-dependent spot unless that tradeoff feels right.
Define the switch
Ask the venue for its weather decision deadline and who has authority to call it. Establish how suppliers hear about the change and whether labor, timing or layout revisions affect their scope. If a change must happen while guests are onsite, identify a clear path for movers.
Weather is not only rain. Wind affects fabric, paper and tall vessels; heat affects flowers and candles; damp grass affects runners and unstable stands. The candle guide addresses flame decisions in exposed spaces.
Make the backup feel complete
Choose at least one detail that works in both places—a pair of floral accents, a considered chair arrangement or a portable sign. Guests respond to a coherent moment more than to the fact that Plan A moved.
Keep both floor plans with the day-of schedule. Label boxes by destination, and share photographs of intended placements. Use the venue checklist to close any gaps before the week of the wedding.