Oil Viscosity Choice for Arizona and California

[1stTimeRX350Owner]

Hi, I'm a new owner and have a question about oil viscosity choices.  The owner's manual says I should replace it with 0W20 full synthetic oil.  That viscosity is a more expensive grade than 5W20.  Since I live in Phoenix and travel to CA and NV but never when it snows or gets extremely cold.  Where I drive, the temperatures can range from 32 to 120 F.  Can I save the money and go with 5W20 instead of the manufacturer's recommendations?