Why is it "partly cloudy" and not "partly sunny"?

Question

It's like saying the glass is half empty!

Answer 1

 ...but you wouldn't say "Partly Sunny" for the night time.

 

Answer 2

 There is NO difference.

 

Answer 3

They say partly cloudy because the sun is always out in the daytime and Clouds tend to determine how much of the sunlight will reach the surface.  Therefore it is always fully sunny and we just don't get to see it b/c of the clouds.  That is why is it partly cloudy. A day with no clouds is a sunny day!

Answer 4

There is actually correct definitions to them and each term has its own technicality.  

Partly cloudy- Means there will be more sunny periods and less cloudy periods though out the day. (It will be sunnier then it will be cloudy)

Partly sunny- Means there will be more cloudy periods and less sunny periods though out the day.  (It will be cloudier then it will be sunny)

Answer 5

Has the meteorologist taken his (her) Prozac yet?

Answer 6

As a forecaster, I would tend to use the description "partly sunny" occasionally, but only for daytime forecasts where the predominent cloud coverage would be mid/upper level clouds such as cirrostratus with some altostratus mixed in. This would produce only occasional sunshine.The rays of the sun make it though cirrostratus (you can still see your shadow) but not through altostratus (the sun appears "muted").

Partly sunny does not apply to a night-time forecast, which lessens it's usage.

Answer 7

add with some rain and you have the irish weather forecast at the height of summer.

seriously we've had all 3 where i am today