The Trident Channeling Enchantment works in non-weather biomes (i.e. Mesa, Desert, Savanna).
This is strange because it summons lightning where no lightning can strike otherwise.
I believe this to be a bug because another Trident Enchantment, Riptide does not work in the non-weather biomes when it is storming so it is inconsistent that the Channeling Enchantment does work.
Steps to recreate:
1. Put Channeling Enchantment on Trident
2. Go to Non-Weather Biome (Desert, Savanna, Mesa)
3. Change weather to Thunder
4. Throw Trident at mob and observe that lightning is still summoned despite being in a non-weather biome. Also note that the Riptide enchantment does NOT work in those same circumstances.
This issue may relate to MC-125919 where Tridents with Channeling work in the End Biomes.
Channeling requires that you see the sky while the weather is thundering, riptide requires that you touch water.