How to detect gleba rain

[freeafrica]

So I've checked out data-raw-planet prototype, and found how the gleba rain is generated. However I have trouble founding how it is applied. Is that inside the core game code maybe?

I saw that it is a player-effect, so maybe I could check if an effect is present with the proper name, to decide if it is raining? However that field type is `Trigger`, not sure how should I inspect that?

Any other method, ideas are welcome of course!