Weather Extremes Speed Up Autumn Colours

The first signs of autumn are arriving early across much of Ireland, with the browning of leaves now accelerating after a spell of unsettled weather followed weeks of summer drought in parts.

August brought prolonged dry conditions that stressed many native trees. The subsequent arrival of heavy rain and strong winds in recent days has compounded the damage, stripping some branches of already fragile foliage. As a result, many parts of the country are reporting an early onset of autumn colour, though much of it is browning rather than the vibrant golds and reds typically associated with the season.

Leaves naturally begin to change colour in September as shorter days reduce the amount of chlorophyll, the green pigment that allows plants to produce food. As chlorophyll levels decline, other pigments become visible, giving leaves their characteristic autumn shades. However, when trees experience heat, drought or storm damage, the process can be disrupted. Instead of a gradual colour change, leaves may wither and turn brown prematurely.

Met Éireann data show that much of Ireland endured below-average rainfall through August, particularly in the east and midlands, before the weather turned unsettled in late August with widespread downpours and blustery conditions. This sequence of extremes has placed additional strain on trees already under pressure from long-term challenges such as pests, disease and soil stress.

While the spectacle of autumn is beginning to appear in woodlands and hedgerows, this year’s display may be muted. Many trees are shedding their leaves earlier than usual, as nature responds to the twin impacts of drought and increasingly unsettled weather.