Defining a Hebridean summer is like trying to catch sunbeams in a fishing net. In many respects it is like this post, you thought it had arrived only to discover that when you took a closer look it had mysteriously disappeared only to reappear a week later.

As a scientist I should quote meteorological statistics: means, percentiles, trends, maximums and minimums, but that would be equally futile as numbers will never explain the intoxication of the fragrance of lady’s bedstraw distilled with clover.

On a late July afternoon the grasses are tickled by the faintest breath of air as we are wrapped in the milky opaqueness of a pearly mist. There is no sense of time as the obscured sun casts no shadow and it could equally be 4.30 am or 4.30 pm. Silent brown butterflies skip amongst the blue haze of the vetch and somewhere the bees sleep replete with nectar. Low tide and the waves are suppressed into ripples, the kelp rising to the surface to undulate like the ochre tresses of mermaids. There is the distant echo of the raucous call of a herring gull, but this demented laughter will not stir the slumbering seals, it just defines the oppressive weight of silence.

It is as if summer, exhausted by the effort of evaporating the morning mist, has lapsed into the dream-time. For a while the sun blazed across the heavens and the night’s raindrops, which adorned leaves and stems with crystal, fell cool on to naked toes. An insistent clatter of squabbling, juvenile starlings, no substitute for the song of the June lark, reminds us that the northern summers are short and soon we will begin to sense a change in the air.

A shiver of cool air marks the transition to evening and the mist metamorphoses into clouds. A sliver of silver light betrays the presence of the sun and defines the horizon – once more land, sea and sky are separate kingdoms. As the tide rises the sea becomes a maze of silken flows and corrugations. A faint line of surf on the whale-backed reef is the counterpoint in the continuum of blue and grey. The distended twilight morphs into the northern night. Two ravens sit shoulder to shoulder on an erratic draped with a lichenous carpet of gold, silently taking the night air like two black-clad widows mesmerised by the song of the seals.

Dawn is announced by mewing gulls, clamoring piping oystercatchers and the sound of waves on the shore as the eastern sky is suffused with a hint of pink, a watercolour wash seeping across the landscape. The brooding somnolent shoulders of Hecla and Ben Mhor are draped in pashmina of cloud which slowly rises to obscure the peaks. Will the sun appear in a blaze of glory to evaporate the mist and herald the blue clear skies of another perfect summer’s day?

The earth turns and it is now August, conjuring visions of the long hot days of old-fashioned seaside holidays, buckets and spades, dripping ice-cream cones and sand encrusted picnics. Is this an English idyll or has nostalgia dimmed my memory? Here August is a prelude to autumn.