You probably have a SVG renderer in memory already, and you already have a frame buffer and/or compositor buffer(s). Why should adding a graphical representation of the weather require more than a few KiB?
Not sure what you think "having an SVG renderer in memory" means exactly, typically the way an SVG renderer works is that you give it a huge chunk of memory and ask it to draw pixel data there from the SVG file. So even though the SVG is small on disk, rendering a 1000x1000 image from an SVG is gonna need a 1000x1000x3 byte pixel buffer (assuming no transparency or HDR shenanigans)
Because a big picture looks pretty sometimes?
Not sure what you think "having an SVG renderer in memory" means exactly, typically the way an SVG renderer works is that you give it a huge chunk of memory and ask it to draw pixel data there from the SVG file. So even though the SVG is small on disk, rendering a 1000x1000 image from an SVG is gonna need a 1000x1000x3 byte pixel buffer (assuming no transparency or HDR shenanigans)