Throwing a trident enchanted with Channeling at a lightning rod during rain summons lightning

I do not know if this is meant to be like this, but I used a Trident with a Channeling enchantment on it during a normal rain by throwing it on a Lightning Rod and it summoned a lightning bolt. Thinking I was actually in a thunderstorm, I threw it on a sheep and nothing happened. Again, I do not know if Lightning Rods are meant to summon lightning even during a regular rain, but I thought I'd report it. My clip take up too much space though, so I made a streamable. https://streamable.com/9b8w9u