Sometimes, the answer is yes! It is attested to that the Habsburg armies of Charles V, during their 1541 Campaign in Algiers, faced major difficulties in using their arquebuses due to rain, as well as due to high winds that would physically blow the gunpowder off of the exposed pans where sparks would be lit. These issues resulted in the development of the Miquelet Lock, which was an evolution of both the matchlock and the wheellock forms of firearms. The Miquelet Lock was the predecessor to the flintlock form of firearms, which were much more resistant to rain and wind preventing them from firing. Flintlocks were first developed in the early 1600s, and would be standard for firearm construction until caplock firearms (that is, those using proto-cartridges which fired within the barrel of the gun) in the 1800s. Flintlock weapons used pans of gunpowder that were fully covered by a steel "frizzen" piece, which would shelter the powder from fire and water, only opening right as the flint struck it as part of the firing mechanism. This greatly improved reliability.
So to answer your question - caplock and similar weapons prior to the 1600s were known to be unreliable in wind and rain, left unable to fire at all, while Napoleonic firearms would be far less susceptible to the same failures. It is worth mentioning, however, that while firearms using flintlock mechanisms were more reliable to fire in rainy conditions, that would not diminish the ancillary issues rain would cause them, in aiming, in the flight of the bullet, and in reloading.