Is it partly cloudy on sunny days to describe the weather?

In meteorological industry standards, sunny days, partial cloudy days, cloudy days and cloudy days are judged by the percentage of cloud area in the sky: it is sunny when the cloud amount is 0%- 10%; 10%-30% partly cloudy; 30%-70% is cloudy; More than 70% is cloudy.

Visually, when it is sunny or partially cloudy, the blue sky is like washing, and there is no cloud or only a small amount of cumulus in Wan Li; Clouds cover most of the sky on cloudy days, mostly cumulus clouds or layered clouds with a small range, through which sunlight can shine on the ground; On cloudy days, a large range of layered clouds cover the sky, which has a great influence on the light transmittance, and generally the sun is not visible.

The word "occasionally" on a sunny day means occasionally and sometimes. So sunny days are partly cloudy, which means it is sunny most of the time, and sometimes there are a few cumulus clouds.