Does weather affect creature spawns?

In practice that means the spawn table you see is built in layers. Location and biome come first, since every Aniimo has designated habitats and you will not find it outside them. Weather and time of day then decide which of that habitat's residents are actually out when you arrive. Standing in the right place is only half of it.

The sharp end of this is that some creatures are only obtainable during a specific weather condition or a limited-time event. Not rarer, not harder. Unavailable. If you are hunting one of those, grinding the correct biome in clear daylight will never produce it, and the fix is to come back when conditions change rather than to keep circling.

Weather also affects the form a creature appears in, not just whether it appears. Location, weather, other environmental conditions, and the in-game time and day-night cycle all feed into that. A species you have already caught can show up as something you have not, so it is worth re-checking familiar spawn points after the weather turns or the sun goes down.

Making the weather cooperate

You are not stuck waiting forever. Upgrading a region's bloom branch unlocks the ability to change the weather there, which turns a conditional spawn into something you can set up on demand. Prismana weather control specifically comes online at 60 percent completion of the bloom graph.

That gives bloom progression a concrete reason to exist beyond the completion number. Until you reach it in a given region, weather-locked catches happen on the game's schedule. After it, they happen on yours.

Not settled: Whether player-triggered weather satisfies the requirement for weather-gated spawns, or only naturally occurring weather does, is not settled. Limited-time climatic events are a separate gate either way, and those run on their own schedule.