Bute's Climate

Overall, Bute's climate is cool with average temperatures between 2oC and 18oC, with extremes rarely exceeding -3oC and 25oC. From May to September, average daily maximum temperatures are between 16-18oC falling gradually to a daily average maximum of around 6oC in December & January.

The driest months are April through to August, with average monthly rainfall of between 60 and 80mm. The wettest months are October through to January, with average monthly rainfall reaching 130mm. However, there is often a great degree of variation in these figures and it is not unknown for this picture to be reversed - with low rainfall in the winter months and higher amounts in summer.

Compared with the whole of the UK and figures for the period 2015-2020, Bute experiences around 130% of the total - in other words, it's about one third wetter here than the UK average. Snow and ice are rare. It's also rare for rain to linger - "four seasons in one day" is a very apt way to describe Bute's climate when low pressure dominates the forecast.

Daylight hours vary between 7 hours in late December to 17.5 hours in late June. Sunrise varies between 04:35 and 08:50, and sunset varies between 15:45 and 22:10 although in the summer months twilight extends significantly beyond these times.

Bute's humidity levels are very low, in fact generally close to 0% from November to May, and rising no higher than 30% in late July / early August.

Bute can best be described as breezy - much of the east coast of the island (where most people live) is relatively sheltered from prevailing winds. April to mid October is generally quite calm overall, with average hourly wind speeds of around 10mph. January is often the windiest month, with average hourly speeds of around 17mph but again, as with precipitation, this can vary dramatically. It's rare to find a totally calm day but they do happen! On the flipside, it's not unusual to experience 30mph winds on non-storm days. Wind direction is predominantly southerly or south-westerly for around 75% of the time overall.

The island is home to a number of open water swimmers who meet year round. Unsurprisingly, our average water temperatures are amenable - ranging from an average 7oC at the lower extreme in March, to an average 14oC in mid August.

Sources: weatherspark.com, statista.com