Warmer than the bottom, and the difference is the whole specification.
In vapour phase the liquid sits below the samples and cools them through the gas above it. That produces a vertical gradient: the bottom of the canister sits close to the liquid temperature and the top sits warmer. How much warmer depends on the vessel design, the liquid level and how frequently the lid is opened.
Two consequences follow. Design around the warmest position a sample can occupy rather than the coldest, because the top of a full canister in a vessel running low is where a problem appears first. And treat the level alarm as more critical in vapour phase than in liquid phase, since a falling level directly worsens the gradient.
Ask any supplier for the gradient data for the specific vessel under a stated liquid level, not a single headline temperature.
