#It is subject to GM interpretation

The spell doesn't say that it freezes water. However, it does refer to environmental effects. Specifically it says that it creates

A blast of cold air

As there is no fluff/flavor text in 5e spells, this blast of air must be actually happening.

This could reasonably be ruled to freeze some water since it is a 5th-level blast of cold air, though the amount and thickness of the ice are up to GM discretion.

As @Pyrotechnical pointed out in the comments, the spell mentions that

A creature killed by this spell becomes a frozen statue until it thaws.

Which should require some pretty intense cold. While not a RAW justification, it does imply that the water in the creatures is frozen, so logically it should be the same for water outside of creatures.

##Personal experience

This happened to me in a game where the players were fighting monsters on the other side of a pond. One of them wanted to cast cone of cold to freeze the pond and allow the fighter to get to the other side faster so I allowed it and described it as (roughly) :

Biting cold air escapes from your outstreched hands towards the pond and the enemies, leaving a layer of frost on the ground and instantly freezing the water.

Then I had the fighter do a DEX check to avoid slipping and shattering the ice, which royally failed, hilarity ensued.

It is subject to GM interpretation

The spell doesn't say that it freezes water. However, it does refer to environmental effects. Specifically it says that it creates

A blast of cold air

As there is no fluff/flavor text in 5e spells, this blast of air must be actually happening.

This could reasonably be ruled to freeze some water since it is a 5th-level blast of cold air, though the amount and thickness of the ice are up to GM discretion.

As @Pyrotechnical pointed out in the comments, the spell mentions that

A creature killed by this spell becomes a frozen statue until it thaws.

Which should require some pretty intense cold. While not a RAW justification, it does imply that the water in the creatures is frozen, so logically it should be the same for water outside of creatures.

Personal experience

This happened to me in a game where the players were fighting monsters on the other side of a pond. One of them wanted to cast cone of cold to freeze the pond and allow the fighter to get to the other side faster so I allowed it and described it as (roughly) :

Biting cold air escapes from your outstreched hands towards the pond and the enemies, leaving a layer of frost on the ground and instantly freezing the water.

Then I had the fighter do a DEX check to avoid slipping and shattering the ice, which royally failed, hilarity ensued.

#It is subject to GM interpretation

The spell doesn't say that it freezes water. However, it does refer to environmental effects. Specifically it says that it creates

A blast of cold air

As there is no fluff/flavor text in 5e spells, this blast of air must be actually happening.

This could reasonably be ruled to freeze some water since it is a 5th-level blast of cold air, though the amount and thickness of the ice are up to GM discretion.

##Personal experience

This happened to me in a game where the players were fighting monsters on the other side of a pond. One of them wanted to cast cone of cold to freeze the pond and allow the fighter to get to the other side faster so I allowed it and described it as (roughly) :

Biting cold air escapes from your outstreched hands towards the pond and the enemies, leaving a layer of frost on the ground and instantly freezing the water.

Then I had the fighter do a DEX check to avoid slipping and shattering the ice, which royally failed, hilarity ensued.

#It is subject to GM interpretation

The spell doesn't say that it freezes water. However, it does refer to environmental effects. Specifically it says that it creates

A blast of cold air

As there is no fluff/flavor text in 5e spells, this blast of air must be actually happening.

This could reasonably be ruled to freeze some water since it is a 5th-level blast of cold air, though the amount and thickness of the ice are up to GM discretion.

As @Pyrotechnical pointed out in the comments, the spell mentions that

A creature killed by this spell becomes a frozen statue until it thaws.

Which should require some pretty intense cold. While not a RAW justification, it does imply that the water in the creatures is frozen, so logically it should be the same for water outside of creatures.

##Personal experience

This happened to me in a game where the players were fighting monsters on the other side of a pond. One of them wanted to cast cone of cold to freeze the pond and allow the fighter to get to the other side faster so I allowed it and described it as (roughly) :

Biting cold air escapes from your outstreched hands towards the pond and the enemies, leaving a layer of frost on the ground and instantly freezing the water.

Then I had the fighter do a DEX check to avoid slipping and shattering the ice, which royally failed, hilarity ensued.

#It is subject to GM interpretation

The spell doesn't say that it freezes water. However, it does refer to environmental effects. Specifically it says that it creates

A blast of cold air

As there is no fluff/flavor text in 5e spells, this blast of air must be actually happening.

This could reasonably be ruled to freeze some water since it is a 5th-level blast of cold air, though the amount and thickness of the ice are up to GM discretion (tread lightly on that frozen pond).

#It is subject to GM interpretation

The spell doesn't say that it freezes water. However, it does refer to environmental effects. Specifically it says that it creates

A blast of cold air

As there is no fluff/flavor text in 5e spells, this blast of air must be actually happening.

This could reasonably be ruled to freeze some water since it is a 5th-level blast of cold air, though the amount and thickness of the ice are up to GM discretion.

##Personal experience

This happened to me in a game where the players were fighting monsters on the other side of a pond. One of them wanted to cast cone of cold to freeze the pond and allow the fighter to get to the other side faster so I allowed it and described it as (roughly) :

Biting cold air escapes from your outstreched hands towards the pond and the enemies, leaving a layer of frost on the ground and instantly freezing the water.

Then I had the fighter do a DEX check to avoid slipping and shattering the ice, which royally failed, hilarity ensued.