An outdoor event needs a backup that can actually be activated, not just a hopeful sentence about moving indoors. Weather affects ground conditions, travel, equipment, catering and the comfort of guests. Build a plan with the venue and relevant suppliers before invitations go out. The useful question is which changes can be made safely, by whom and at what point, rather than whether the forecast looks pleasant today.
List what depends on outdoor conditions
Walk through the programme and identify exposed activities, equipment and routes. A covered stage does not solve a slippery approach, a wet registration desk or a catering station without suitable shelter. Include setup and dismantling periods, because suppliers may be working outside before guests arrive. Ask each supplier which conditions affect its equipment and what information it needs to make a decision.
Look at the site after rain if possible, or ask the venue about known drainage and surface problems. Grass that looks level and firm during a sunny visit can behave differently when vehicles, furniture and many guests use it. Avoid improvising structural or electrical solutions. Temporary structures and powered equipment need appropriate planning and competent suppliers for the actual location and conditions.
Reserve a realistic alternative space
Check that an indoor or sheltered alternative can accommodate the essential activity, not merely the number of people standing together. Consider seating, access, toilets, catering, power and the sound environment. Ask whether the space is exclusively reserved or remains available for another booking. A backup room that might be occupied is an unresolved risk rather than a plan.
Create a simplified version of the event for the alternative location. Some displays, performances or meal formats may need to change. Decide which elements matter most and which can be reduced or removed. Preparing that version early lets suppliers quote and plan accurately, rather than asking staff to reproduce an outdoor event in a smaller room at the last moment.
Agree triggers and decision authority
The decision should combine forecasts, site observations and the limits specified by suppliers or venue management. Use the equipment-specific limits confirmed by the venue or supplier; different structures require different operating limits. Ask the responsible professionals what conditions apply to their equipment and how monitoring will work. Record who can stop an activity immediately and who coordinates the wider event response.
Set decision times linked to practical tasks. A room reset, delivery change or transport update may need hours rather than minutes. Name the person who will issue the final instruction and a deputy if that person is unavailable. Staff should not receive conflicting directions from several organisers watching different weather apps. One coordinated decision is easier to implement and explain.
Prepare the message before it is needed
Write short guest messages covering the likely changes: a different entrance, an indoor programme, a revised start or a cancellation. Explain where updates will appear and provide an event-day contact. Include suppliers in the communication plan with their own delivery and access instructions. A social post alone may not reach a driver who is already travelling to the original entrance.
Check how signage and welcome staff will direct people who miss the update. Keep routes accessible and avoid moving a queue into an unsuitable covered corner. If the event continues in a modified form, tell guests what has changed before they arrive so they can make an informed decision about clothing, travel and participation. Clear information reduces frustration even when the programme is less elaborate.
Rehearse the switch and keep a record
Walk through the change with the venue: who moves equipment, who checks the new room, who contacts speakers and who confirms catering arrangements? Keep the essential phone numbers and drawings available offline. Ask what happens if conditions change during the event, not only before it starts. The response needs to work when guests and staff are already on site.
Afterward, record which decisions were timely and where the backup proved incomplete. Update the site notes rather than treating a fortunate dry day as proof that the plan was sufficient. A good weather plan protects the purpose of the gathering while recognising the limits of the site and equipment. It makes a change manageable because the difficult questions have already been discussed.
Further reading: HSE: getting started with event safety.
