Can this be left outside in any weather type? I want to put this as a landing mat for my child's slide as it is too steep.

We recommend using our Playground Swing Mats when you're looking for a soft landing that can hold up to the elements (https://www.flooringinc.com/playground-tile/swing-mat.html). These mats are fall-rated up to 4' and are designed for this exact use.