On a clear sunny day, around noon,

you receive around 800-1000 W/m² solar power.

This is when the sun is at its highest point and the intensity of the sunlight is strongest.

When you are under the shade of a tree

you receive around 80-200 W/m² solar power.

Roughly around 10% to 20% of the direct sunlight

With Thin or light cloud cover

you receive about 50% to 70% of the direct sunlight.

This corresponds to roughly 400 to 700 W/m²

With Moderate Overcast

you receive about 30% to 50% of the direct sunlight.

This translates to roughly 240 to 500 W/m²

With Heavy Overcast

Under heavy overcast conditions, the sunlight is further reduced to about 10% to 30% of the direct sunlight.

This means you are still getting roughly 80 to 300 W/m² solar irradiance

tl;dr

When the sun is out, you should be out too.

Doesn't matter if you are in shade or if there are clouds

YOU.

ARE.

STILL.

GETTING.

THE.

BENEFITS.