Char-Broil 2-3 Burner All-Season Cover – Link

Amazon has this currently marked down to just $8.99.

• Medium-duty grill cover protects your grill against damage from the elements
• Designed to fit grills with 2 to 3 burners, up to 52-inches wide
• 300D polyester material with PVC inner coating
• Convenient side closure straps keep cover securely fastened