I would like to use them on an exterior deck, will they perform well with temperature variations and sunshine?

You can install our 8mm Strong Rubber Tiles - Designer Series on our outdoor deck. These tiles are slip resistant whether wet or dry and are resistant to mold and mildew. These tiles are very easy to clean and maintain and can expand and contract with extreme heat and cold. The only thing you will notice with these tiles is that they will fade in direct sunlight.