It depends on numerous factors. One is how windy is it? Another, “is it alright with you and your soon to be spouse if the candles blow out either before, during or after the ceremony?” And, if you have a hurricane globe for around the Unity Candle, what will you put around the individual taper candles to keep them from blowing out? Keep in mind that it’s not possible to put hurricane globes around the tapers because you won’t be able to reach in without burning yourself.
My suggestion if you want to have one outside is to make a back up plan for inside. It may work to have the lighting of the candle just prior to the cutting of the cake.
Also, make sure that the people lighting the individual tapers have practiced with the lighter that you have for them, as not all lighters light the same way. And, have the person escorting them up to light the candle know how to light the lighter just in case.
If the table you have the candle on has to have a table cloth, make sure that the wind won’t grab hold of the table cloth and knock it over.
Share your thoughts. 🙂