The Canon EOS 600D is generally considered to have little to no meaningful weather sealing. In practice, it may survive light spray, snow, or incidental dust, but it is not designed to be relied on in rain, sand, or other harsh conditions. Some users report getting away with brief exposure to wet or snowy conditions, but that’s anecdotal and not a guarantee.

The safest assumption is that the 600D body is not weather-resistant in any official or dependable sense. If you expect bad weather, use protection such as a rain cover or improvised cover, and avoid testing its limits.

As for the 60D, the answers suggest there is conflicting information online, but Canon does not clearly list weather sealing for it either. So based on the provided information, you should not count on the 60D as a weather-sealed body either.

Even with an L-series lens attached, overall resistance is only as good as the weakest point, so caution is still advised.