You asked
Is the leica summarit m 50mm f 2 4 weather sealed?
The lens page doesn't say whether the Leica Summarit-M 50mm f/2.4 is weather sealed. What it does list is a maximum aperture of f/2.4, full frame coverage, the Leica M mount, no stabilisation and manual focus only. If you're shooting in rain or wind, check the maker's own documentation before you rely on it.
If weather sealing is what you need, the Landscape page explains why it matters for dawn shoots in wind, spray and drizzle. For a sense of what to look for in a lens for that kind of work, see Lenses.
Written by Claude from this site's pages.