TORONTO, May 8 (Reuters) - Canada's oil and gas producers shut down some production after Alberta was hit by an unprecedented wildfire season, although rain and cooler weather are expected to bring some relief on Monday. Canada is home to the world's third-largest reserves, and most of these are in northern Alberta's vast oil sands. NuVista Energy (NVA.TO) said on Monday it had temporarily shut in about 40,000 boepd as a precaution. In neighboring British Columbia, several communities remained under evacuation orders after heavy rain last week and flood warnings stayed in place. ($1 = 1.3319 Canadian dollars)Reporting by Denny Thomas; Editing by Andrew HeavensOur Standards: The Thomson Reuters Trust Principles.

---