That's according to the European Union-backed Copernicus Climate Change Service on Tuesday (August 29).
Fueled by gale force winds and hot weather, the fire that began near the city of Alexandroupolis quickly spread across the Evros region.
It killed at least 20 people last week, making it Europe's deadliest blaze this summer.
A European Commission spokesperson outlined the body's relief efforts.
"So most notably in Greece's Alexandroupolis region we are facing the largest wildfire ever recorded in the EU. In this context, we have mobilized 12 aircraft from our rescue fleet together with over 400 firefighters and 60 vehicles."
Aircraft and hundreds of firefighters from Serbia, Slovakia, the Czech Republic and Albania are battling the flames. This is Czech commanader Jiri Nemcik:
"It's very difficult according to the temperature, wind, and size, or the space where the fire is. So it's on 100 meters and the development of the fire is very dynamic so it's very dangerous."
The flames have turned swathes of lush greenery into scorched earth and destroyed homes and livelihoods.
The Copernicus Emergency Management Service said the fire had ravaged over 310 square miles at least.
And New York City takes up 300.5 square miles.
All but one of the dead are presumed to have been migrants who crossed over from Turkey.
Authorities fear more bodies may be found when the flames are put out, as Evros is a popular crossing into the EU for thousands of migrants and refugees each year.
Summer wildfires are common in Greece but the government says extreme weather conditions which scientists link to climate change have made them worse this year.
