How Do You Plan an Outdoor Ceremony for 18,000 People When It Might Rain?
By Amanda Rospond | Experience Producer, PC Events + Experiences
Seating opens at 7 a.m. At 9:15 the ceremony begins with a procession into the Main Quadrangles. Afterwards, 18,000 graduates and guests make their way to six ceremony sites across the University of Chicago campus, and the date does not move for weather.
That is the brief for Convocation, the university's largest and most logistically demanding event of the year. PC Events + Experiences has supported it since 2024, and in 2024 and 2026 it rained. Here is what outdoor event planning at that scale involves, how we work alongside a university team that already runs ceremonies well, and what a bit of rain looks like when the plan was written a year earlier.
WHAT DOES AN 18,000-PERSON OUTDOOR CEREMONY TAKE?
Numbers first. They set the size of the problem.
18,000 graduates and guests
Six outdoor ceremony locations
35 PCXP team members onsite
Three full event days
Ten days of install
More than 15 vendors, from water suppliers and program printers to multiple tenting companies, AV, catering and fencing
Ten days of install is the number worth sitting with. Each of the six sites has its own site map, and each map has to account for flooring, tenting, AV, catering, restrooms, seating, signage, ADA requirements and storage. Change one thing, and it ripples: the tables catering needs have to match the linens the rental company is bringing, at every site, in whatever weather shows up during the build.
Fifteen vendors is also fifteen sets of quotes to check against what the university actually asked for, which is why choosing the right vendors matters as much as managing them.
WHO DOES WHAT WHEN THE UNIVERSITY HAS ITS OWN TEAM?
The Office of University Events and Ceremonies runs Convocation with an internal team of six. They run events all year. They know the traditions, the academic protocol, the stakeholders and the campus better than any outside partner will. What they needed from us was stability: one team holding the vendor network, the site maps and the logistics together while departments and faculty pulled in different directions.
So we fit into the structure they already had. We joined the university's existing workstreams for signage, volunteers, staffing, AV and tent rentals, met with their team monthly for more than a year, and ran periodic full-team meetings with every vendor and the university departments involved.
In the first year, we mostly listened. Large institutions decide through several layers of approval, and the fastest way to slow that down is to arrive with a list of changes. We offered suggestions only where we could show a clear improvement. One of them, a revised event map and signage design, went through weeks of review by the design, communications and planning teams before it was approved. It improved internal coordination and made the day easier for guests to navigate.
That is the model for any institution with its own events office: reinforcement, not replacement. Your team keeps the institutional knowledge. We add the event management support for the one event that outgrows any single office.
WHAT'S IN THE RAIN PLAN?
At 18,000 people, a rain plan is a build decision, not a day-of decision. There is no indoor room big enough to move a ceremony this size into, so the plan is about keeping six outdoor sites workable in weather. Four pieces carry it.
Tents. Convocation uses a countless number of tents, and every site map shows where cover goes before install starts.
Flooring. Planned site by site. Wet turf under thousands of guests turns to mud, and mud closes accessible routes before it closes anything else, so flooring and ADA routing get planned together.
Comms. One attendee communication plan, with guests told what to expect before they arrive. The measure of whether it worked is how many people call or email Convocation Headquarters on the day.
The call time. The hour the weather decision gets made, and the person who makes it, agreed in advance and written into the run of show. Deciding when to decide removes the worst argument of the morning.
Lightning is the one condition that stops an outdoor ceremony outright. Tents do not protect anyone from it, and the lightning safety guidance from the National Weather Service is plain: the only completely safe place is inside a building or vehicle, and large groups need extra time to get there. That is why shelter gets identified during planning, not found on the day. For crowd and weather safety more broadly, the Event Safety Alliance publishes the guidance most producers work from.
Then the people. Our Experience Producer trained all 35 team members through pre-event and onsite sessions, so everyone at every site knew the plan before they needed it.
WHAT HAPPENED WHEN IT RAINED?
It rained on the day in 2024. A bit of rain, as we put it at the time.
The ceremony ran. No on-site medical or security issues were reported. Calls and emails to Convocation Headquarters went down, which told us the communication plan had done its job before anyone needed to ask where to go.
That is what a rain plan buys. Not a dry day. A day where weather is one more logistics item, handled by people who already knew what to do.
WHAT DID THE CLIENT SAY?
Katelyn Doyle is Senior Associate Director in the Office of University Events and Ceremonies. Her summary of working with us:
“This was the best planning experience I’ve had in a really long time.”
Katelyn Doyle, Senior Associate Director, Office of University Events and Ceremonies, University of Chicago
We value that line because it is about the planning, not the day. Guests remember the ceremony. Her team lived with the year of meetings, quotes and site maps that came before it.
WHAT DOES THIS MEAN FOR YOUR OUTDOOR EVENT?
Most outdoor events are smaller than Convocation. The method holds at any size.
Write the rain plan with the site plan, not after it.
Name the decision-maker and the call time in the run of show.
Price tenting and flooring into the budget early. Adding cover late is the expensive version.
Identify real shelter during planning and know how long it takes to get your crowd there.
Tell guests what happens in weather before they arrive, so the message on the day is a reminder, not news.
We covered the wider principles in Producing a Great Outdoor Event Isn't Just About the Weather. For how guests move through a site from arrival to exit, start with mapping the attendee journey.
FREQUENTLY ASKED QUESTIONS
How far ahead should you plan an outdoor ceremony for thousands of people?
A year or more at this scale. We met with the University of Chicago's team monthly for more than a year before Convocation, and tenting and flooring were in every site map from the start. The rain plan is not a late addition.
What goes into a rain plan for an outdoor event?
Tents, flooring, attendee communications and a call time. The call time is the hour the weather decision gets made, with one named person making it, agreed before anyone is standing in the rain.
Can you move an 18,000-person ceremony indoors if it rains?
Usually not. There is no indoor room that size. The plan keeps the outdoor sites workable instead: cover, footing, clear guest messaging, and a lightning procedure that gets people to real shelter if a storm moves in.
Do you work with universities that already have an events team?
Yes, and that is the usual arrangement. At Convocation, the university's Office of University Events and Ceremonies leads with its own team of six. We join their workstreams and take on vendor coordination, site logistics, staffing and onsite execution.
How many vendors does a large outdoor ceremony need?
Convocation works with more than 15, including water suppliers, program printers, multiple tenting companies, AV, catering and fencing. Periodic full-team meetings with every vendor and university department keep them working from the same plan.
What does lightning mean for an outdoor ceremony?
It means stopping. Tents do not protect against lightning, so the plan has to name real shelter and allow extra time to move a large crowd. The National Weather Service advises waiting 30 minutes after the last thunder before resuming.
WE GET WEATHER DONE.
Planning a commencement, a convocation or any outdoor ceremony where the date cannot move? Ask us about an outdoor event that gets rained on. Then tell us about yours, whether it is in Chicago or wherever your campus is.
Hero photo: University of Chicago Convocation 2024, by Jason Smith.
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