The difference between Cheerful and Sunny

When used as adjectives, cheerful means noticeably happy and optimistic, whereas sunny means featuring a lot of sunshine.

Sunny is also noun with the meaning: a sunfish.

Sunny is also adverb with the meaning: sunny side up.

check bellow for the other definitions of Cheerful and Sunny

Cheerful as an adjective:

Noticeably happy and optimistic.
Cheerful as an adjective:

Bright and pleasant.

Examples:

"They enjoyed a cheerful room."

Sunny as an adjective (of weather or a day):

Featuring a lot of sunshine.

Examples:

"Whilst it may be sunny today, the weather forecast is predicting rain."
Sunny as an adjective (of a place):

Receiving a lot of sunshine.

Examples:

"the sunny side of a hill"

"I would describe Spain as sunny, but it's nothing in comparison to the Sahara."
Sunny as an adjective (figuratively, of a person or a person's mood):

Cheerful.

Examples:

"a sunny disposition"
Sunny as an adjective:

Of or relating to the sun; proceeding from, or resembling the sun; brilliant; radiant.