Episode 6’s script confirms it

Image from preview.redd.it and submitted by Zeegss
image showing Episode 6’s script confirms it

cdubs88 on August 6th, 2019 at 10:48 UTC »

Drogon was just trying to melt all the snow in kings landing

mynameisnoone1993 on August 6th, 2019 at 10:57 UTC »

Huh? I thought it was ash?

And wasn’t winter coming at the end of season 7 when it started snowing when Jaime left for the north...then all of a sudden it was, like, a desert in season 8 with no snow in sight?

Wtf is with all this shit that makes no sense!!

pat1308 on August 6th, 2019 at 11:51 UTC »

Relevant parts of the S08E06 script:

"Snow has begun to fall and will continue to fall throughout this day."

" Tyrion walks past the ruined map room, snow starting to cover the ash and rubble."

"Dany stands in the Throne Room. It looks just like it did in her vision, only the area behind the Iron Throne has been destroyed altogether. I.e., no window behind throne, Lannister or otherwise.

The snow falls lightly through the collapsed roof as she steps past the pillars, down the central aisle. Rubble from the fallen roof is visible on the floor, covered in a layer of snow.

For a few seconds, the conquering queen disappears and she looks like a young girl again, entranced by the beauty of the moment, and the object of her greatest desire.

It is right there. The reason for her long journey across two continents, the endless conflicts, the deaths of her loved ones:

The Iron Throne.

She slowly climbs the snow-covered stairs."

"[Dany's] eyes are already glazing over. Winter has come to the Throne Room. Dany lies dead in his arms, Pieta-style, as the snow drifts down."

"Tyrion looks at the crumbled walls rising up on either side of him, still patched with snow on the top."

So yeah, it's indubitably snow.