The perfect sunbeam weather occurs on humid, hazy, summer
mornings that follow an evening or nighttime of showers or
thunderstorms. The air is filled with fog and haze particles
which makes sunlight visible by diffraction, reflection, and
scattering of the light. Shadows from trees or clouds provide
the contrast needed to highlight the individual rays of light.
Sunbeams are really crepuscular rays that can occur any time of
year. They originate from clouds, trees, buildings, or even
windows. On the morning of June 17, the crepuscular rays shining
through the trees near Oakton, Virginia were particularly vivid
and well-defined. Thunderstorms occurred the previous evening
which was followed by light ground fog in the morning that set
the stage for the light show. Read below for more photos of the
sunbeams from June 17.