Outdoor wedding in march?!

If you are hoping to just do a ceremony outside and the reception inside, I would go for it. The amount of time spent outside for a ceremony could be worth it and if guests are aware of the timing, they can dress appropriately.

I would highly suggest a Plan B. We live in Canada you never know what you will get at any time of the year. Ask your venue if they offer Plan B, you would be surprised on how many do.

Plan B for indoor ceremony may be wise to seek for a march wedding since the weather can be unpredictable. Taking chances for a cold winter/spring season wedding would require guests to wear their jackets which you don't want.

My daughter was born in the beginning of April and there was a snow storm. This weather is so unpredictable.

To be honest, the weather here is sooo unpredictable during that time of year for an outdoor wedding - Unless it has meaning to you, may be worth looking at other options. Are the prices for end of March and April the same at that venue? We found that those months were in the same price range when we looked at venues - We ended up choosing Friday, April 29th and saved a bunch by having it on a Friday literally a couple of days before peak wedding season. The weather was a touch chilly but not unbearable and otherwise perfect. We bought scarves/wraps for our guest since our ceremony was in an indoor/outdoor gazebo and there were beautiful grounds for our guests to walk. They were a huge hit with the ladies who attended and I definitely recommend little things like that - Maybe even potentially umbrellas if you choose an early spring date!

Let's not kid ourselves, end of March won't be warm, especially in the GTA. It might not be freezing cold but it's not warm enough for most people to sit outside for 30+ minutes wearing formal wear, especially formal dresses. The highest temperatures in Mississauga in March for the past few years is still under 20 and often, it goes below zero. With wind chill on a roof, it'll be even colder.

If you absolutely want the roof top in March, I would save it for pictures between the two of you. I'm sure your venue has an indoor backup for the ceremony. But if you are making your guests sit out there during that time for prolonged periods, make sure you let them know so they can dress accordingly (and maybe provide a hot beverage for the ceremony as a gesture.)

The temperature could vary in March for better or worse depending on your location. It might be worthwhile to check what the weather is usually like in March in that area.

Also, before you change your plans perhaps you could check to see if your venue offers an "indoor Plan B" in case the weather does not permit an outdoor ceremony. If they do, and they are willing to work with you then you should be okay.