What's the difference between 'Partly Sunny' and 'Mostly Cloudy'?

Partly sunny? Or Mostly cloudy? Sounds like the can be interchangeable but the National Weather Service has specific definitions on each term used to describe cloud cover.

Partly Sunny – Or Partly Cloudy?

Intro Guide Part One: Mostly Sunny vs Partly Cloudy – janesweather

Do Partly Cloudy And Partly Sunny Mean The Same Thing? See How The National Weather Service Defines All Forms Of Cloud Coverage In The Sky

Partly sunny' vs. 'mostly cloudy': What's the difference?

Every time I look at the weather forecast.. : r/AdviceAnimals

Partly Cloudy vs Partly Sunny - Difference and Comparison

What's the difference between 'mostly sunny' and 'partly cloudy'? - Quora

Weather: Dreary and mostly cloudy

Weather Chart & Wheel Weather chart, Weather cards, Chart

Ask Ellen: What's the difference between partly cloudy, partly sunny?

What's the difference between Partly Cloudy and Partly Sunny?