Sorry but it's not a blue moon. A blue moon is the second full moon in a calendar month... since each full moon happens on average every 29.53 days... and this is only the 20th of Aug... can't be a blue one.
This month's full moon actually is tomorrow on the 21st. There are several "names" for it depending on which culture did the naming... Sturgeon Moon, the English name is Grain Moon and some other names include .... Red Moon, Green Corn Moon, Lightning Moon and Dog Moon.
The fishing tribes are given credit for the name ( Sturgeon Moon ) since sturgeon were most readily caught during this month.