Natural Gas Stocks Inventory in Spain increased to 20.80 TWh on Sunday March 1 from 19.97 in the previous day. Natural Gas Stocks Inventory in Spain averaged 23.99 TWh from 2011 until 2026, reaching an all time high of 35.91 TWh in September of 2024 and a record low of 8.79 TWh in March of 2011.