IR receivers that are rated "CFL friendly" or "Plasma Proof" should be ok to use outdoors.

Since IR receivers are not weatherproof, you will have to shelter the unit in some manner. You can use a weatherproof outlet cover. Open the cover when you want to use the pickup. This has the advantage of cutting the receiver off from all sunlight when you are not using it, which may reduce random IR noise throughout your system.

You should try to avoid exposing the receiver to direct sunlight at all times.

Expect IR range to be greatly diminished on bright days.