Wedding reception outside

Where (state) and when (month) is your wedding?

I just read your other comments. If your venue has a covered Pavillion that can fit all your guests, you are fine. If not, you need to seriously consider a tent.

Pennsylvania and July!

You're kidding right? Outside in the rain?

Call a tent company. Get an estimate. In July? It's not only rain you should worry about, it's heat. If you think that fans and water will be the answer in 100 degree heat....you're wrong.

Girl, the temps in July are averaging in the high 80's. You need an indoor venue. Someone's gonna get heatstroke.

Rain is the least of your worries.

http://www.accuweather.com/en/us/philadelphia-pa/19102/july-weather/350540

You definitely need a plan B for weather!!

https://www.weddingwire.com/wedding-ideas/etiquette-advice/hurricane-wedding

Wait... Didn't you say that your space has a pavilion? Can't you use that?

Sounds to me like you need an tent with AC, not to keep rain out! I was in a wedding on July 30th on the north shore of Boston and the day was gorgeous, not too hot at all, and an indoor reception. But we went outside to cool down after being on the dance floor and it didn't help at ALL! The weather was too warm even at 8pm to cool us down. AC, AC, AC.

The Mid-Atlantic in July? Are you from PA? It can easily be in the 90s that time of year. Even higher with the heat index.

I would find an indoor venue.

ETA: or get a tent with AC, that's a good compromise.

You don't have to rent a tent. The cost for our venue was too high so our backup plan is to provide white umbrellas during the ceremony which will be no more than 20 minutes. The reception will be covered so no worries there.

^^^^