Thirswik's Unnatural Rain

Over an hour, you slowly absorb five gallons of liquid you touch.  This liquid gets deposited into a reservoir in an extradimensional plane.

Once the reservoir is filled, you may take an action to infuse the atmosphere above you with this type of liquid.  A spherical vapor cloud forms at the highest unoccupied point directly above you up to 720 feet up and spreads in all directions to a radius of 360 feet.  As long as you maintain concentration, light rain falls from the cloud. There is no limit on how much volume it will rain. The rain does not deplete the reservoir or the cloud.  Natural forces like wind can affect and move the cloud and the rain. You may take a bonus action to end the rain and dissipate the cloud manually.

You may take an action to instantly summon the five gallons of liquid to a point you can see within 10 feet of you, doing so breaks your concentration.  Once you do this, or take a long rest, your link to the extradimensional plane is destroyed and you no longer have the ability to create a vapor cloud or summon the liquid.  There is no way to retrieve liquid left in an extradimensional plane other than the wish spell.

Any kind of liquid can be used.  The rain retains all the properties of the original liquid.  If the liquid is caustic, has extreme temperature, or causes damage in some way on contact, it can damage you as you touch it to cast the spell and it can cause damage wherever the rain falls.  Similarly, if the liquid has magical effects on touch, it can affect you as you cast the spell and wherever the rain falls. If the liquid has some effect upon being consumed by a creature, such as alcoholic beverages or magical potions, these will take effect as usual if a creature consumes a sufficient amount of rain.