What does the Weather Radio really do?

[Serp]

It seems really pointless. Is it just there to be annoying for the cell phone?

[UnluckyLucky]

Well it tells if it's about to rain or something I guess.

[windfisch]

Knowing when it starts raining while being underground can be useful to know. It increases spawnrate, fishing power and certain enemies spawn only when it#s raining - mentionable are the nimbus (nimbus rod) and the ice golem (ice feather, frost core)

[TurtleCage]

There are a handful of functions rain causes. You'll receive a 20% bonus to fishing, mobs unique to rain will emerge (Raincoat zombies, walking goldfish, etc) Water leafs will spawn, worms are more frequent in jungles, npcs will return to their homes. This also helps you track HM Mobs who spawn in certain weather conditions like Ice Golem, who spawns in blizzards (in HM)

[ShukazoPenguin]

Originally posted by windfisch:

Knowing when it starts raining while being underground can be useful to know. It increases spawnrate, fishing power and certain enemies spawn only when it#s raining - mentionable are the nimbus (nimbus rod) and the ice golem (ice feather, frost core)

A very useful fact.

[Serp]

Some of this I didn't actually know, like the fishing boost, so thanks for the info! But what about the wind speed? Is that pointless?

(Also I completely forgot that it tells whether it's raining or not. Derp :P)

[itssirtou]

Mostly its just useful if your spending a lot of time underground but hunting a rain drop, like the Nimbus rod or Rainbow bricks.

Its also useful in Fishing, I'm not sure if the rain is factored into fishing power directly or not...
http://terraria.gamepedia.com/Fishing

[Chubblezap]

The wind speed is actually used for determining which way the North Pole's projectiles will fall.

[Serp]

That's a thing? I thought things like the book of skulls were just random

[prpl_mage]

Also, if you open up your inventory, you'll notice that the information from the weather radio doesn't show. That's because you can click the icons to remove desired informations.
I personally remove weather and speed for example.

[Serp]

I use it interchangeably. Like if I'm looking for a probe, I just turn on Time, Rare Creatures, Creature Count, and Treasure for the heckuvit.