This question was migrated from the Bicycles SE to the German language SE. People reading this answer: I do not know any German, so a lot of what follows below was derived from Google Translate. Do note the technical information discussed in the next paragraph, as it may be helpful; I've tried to make it easier for a lay audience to understand.
In bicycles, we normally speak of wet (chain) lube and dry lube. "Wet lube" in English tends to refer to oil-based drip lubricant. In contrast, a "dry lube" is typically understood as a drip lube which is based on wax suspended in or dissolved in a solvent. When the solvent evaporates, the chain is relatively dry. (Note that waxes are solid hydrocarbons, i.e. they're like oils in many respects but the hydrocarbon chains are longer, such that waxes are solid at room temperature). Wet and dry here don't necessarily distinguish between weather conditions, but wet lubes do tend to do better in wet conditions than dry lubes. (However, not all wet lubes may be as good in wet weather, and some dry lubes can take a bit of rain.)
This paragraph is a technical note for cyclists (remember that the question was originally on the Bicycles SE, so German SE readers can skip to the next para). One thing that people may not appreciate is that riding in the rain is pretty hard on the bicycle. The chain is getting doused in water, which tends to wash away lubricant. Additionally, you're getting road spray, which has dirt suspended in it, onto the chain. The dirt combines with any residual lube to act as a grinding paste. So, unfortunately, it would actually be better to clean the chain and relube it after it rains. It would be better to do a full clean (e.g. use a chain cleaner or take the chain off to clean it), but you also do not have to let the perfect be the enemy of the good; if you are pressed for time, you could just wipe the chain down and lubricate it.
I don't know German, and I would definitely defer to a German speaker here. In general, if you don't use exact terminology in a foreign language, the listener may be able to deduce your meaning from the context, although the finer points are obviously harder to convey. Tour Magazine is a prominent German road cycling magazine. This article appears to discuss lubricant testing. The headline is:
30 Kettenöle, Wachse, Schmierstoffe für Rennradketten
Ketten appears to refer to chains, and öle to oil, so Kettenöle would likely be understood similar to a wet lube in English, with the caveat that we don't know if the listener would be able to discern your intent for a rainy conditions lubricant. Google Translate renders "Wachse" as "waxes", and "Schmierstoffe" as "lubricants".
I don't know if German-speaking listeners make a distinction between lubricants in general (e.g. schmierstoffe or similar words) and oils (e.g. kettenöle). In English, I would probably think of lubricants as the general category, and wet lubes (again, they tend to be oil based) as the most common type of lubes, dry lubes as another type, and waxes as a subset of dry lubes (or it's also valid to think of them as distinct).
Without knowing German, I can tell that the word/phrase you proposed in the comments contains the word for rain. I can't comment on how it might be interpreted by someone who speaks German and not English, but it could suffice to start. You might also try using Google Translate in the store, but I suspect you might want to try to input as simple English as possible. For example, "lubricant for wet conditions" would come out as "Schmiermittel für nasse Bedingungen". This sounds like it might be wordier than necessary, but hopefully a German listener would be able to determine the intent.