What's the shape of the Control Weather spell? (if any)

Question

We have this rule in the Player's Handbook, p. 204:

Spells such as burning hands and cone of cold cover an area, allowing them to affect multiple creatures at once. A spell's description specifies its area of effect, which typically has one of five different shapes: cone, cube, cylinder, line, or sphere. Every area of effect has a point of origin, a location from which the spell's energy erupts. The rules for each shape specify how you position its point of origin. Typically, a point of origin is a point in space, but some spells have an area whose origin is a creature or an object.

However, not all Area of Effect spells fit into one of those five shapes. For example, Tiny Hut creates a dome, and Wall of Force creates a wall.

But I'm specifically interested in Control Weather:

Range: Self (5-mile radius)

Spell entry: You take control of the weather within 5 miles of you for the duration. [...]

My guess is that the area is defined by a circle with a radius of 5 miles, without any limitation in terms of height. This would make sense to me because you're controlling the local area's precipitation, temperature, and wind within the atmosphere.

Answer 1

You're right, a radius within 5 miles.

You take control of the weather within 5 miles of you . . . .

However, the range shows a sphere, and 5 miles is 5 miles. There's nothing contradicting that. There is no mention of a cylinder or shape at all, except for "5-mile radius" and "within 5 miles of you".

Really, though, worldbuilding is pretty important here. The spell makes a lot of assumptions, including but not limited to that there are things such as "climate" and "season" where the spell is cast.

The weirder the environment, the more important that the player and DM have a discussion beforehand about how the spell is going to work.

Answer 2

It's a Sphere

The PHB explains this about sphere-shaped spells on page 205:

You select a sphere's point of origin, and the sphere extends outward from that point. The sphere's size is expressed as radius in feet [...].

This is what Control Weather does, though it is described differently as other sphere spells. First of it defines the radius in miles, instead of in feet. Then this spell pre-defines the point of origin, as being the caster themself, where other sphere spells such as Fireball let you choose the point of origin within their Range, which leads me to the third difference: the radius of the sphere is defined inside that Range attribute, in addition to being explained inside the spell description, while other sphere spells only have them in the description.

Contrast this also with the Fear spell, which also has a Range of Self with a further explanation of its diameters inside brackets afterwards, only this time it's a cone. It also has it's range both described at the Range attribute and inside the description. Control Weather follows the exact same pattern, just telling us a radius, instead of a cone. A radius declaration in this case telling us, that it's sphere shaped.

Also from a game play and realism perspective having a sphere with a limit of 5 miles, including the height makes a lot of sense. Imagine being able to control the weather all the way up in space (which is apparently 50-62 miles in earth's atmosphere) or all the way up to a moon, the sun, or a another star or planet that just happens to be exactly above your character.

Answer 3

A sphere.

The fragment you cited mentions the five most common shapes for spells: cone, cube, cylinder, line, or sphere. What you're calling a circle is basically an infinitely tall cylinder. Even a spell such as Circle of Death is actually a sphere (though to be fair it does clearly state that in the description, unlike Control Weather). Something as important as unlimited vertical range would probably be mentioned in the text of the spell.

The cylinder interpretation poses some issues, such as, what happens if the caster happens to be standing on a wall, somehow? Is the cylinder face relative to the surface they're standing on, or to the horizon? Generally I'd go with the simplest option - that is, if we're given a radius with no other stipulations, the shape is a sphere. Plus, "within 5 miles of you" means just that, regardless of the direction.

But perhaps most importantly, take note of the pictogram of a sphere in the D&D Beyond Control Weather spell description:

Range/Area
Self (5 miles )

I think this clearly means it's supposed to be a sphere with the radius of 5 miles centered on yourself.