This works great from the new Windows Terminal (using PowerShell 7):

  Invoke-RestMethod http://wttr.in

For some reason they recommend that early in the readme, but not down in https://github.com/chubin/wttr.in#windows-users where they discuss various issues on Windows.

EDIT: I see now that lzybkr already suggested using the even shorter alias `irm` for `Invoke-RestMethod`. Nice!