Climate Comment For August 2020: Almost Normal!

Submitted by Bill Caulfeild-Browne

The mean temperature for the month was just above the normal of 18.3C, reaching 18.9C. The warmest temperature was 29C on the 14th and the coolest was on the last day of the month when the mercury sank to 10.2C. This was a gentle reminder that single-digit temperatures will soon be in our future (though as I write this we have another three weeks of summer yet to come).

While the thermometer behaved normally, the rain gauge did not. This was the second wettest August I have recorded. The wet stuff came down to a depth of 118 mm, a level only surpassed by the 134 mm we got in 2018. 

This continues the decade long trend to wetter years. In the last century Tobermory’s average annual precipitation, which includes snow, was 808 mm. In the last ten years we have averaged 946 mm per annum, a 17% increase.

The pattern of rainfall seems to have changed too. We actually get fewer wet days in the summer months but more downpours. This August had just six wet periods – but three of them accounted for 107 of the 118 mm. The storm overnight on the 26/27th delivered 53 mm in record time, causing a lot of washouts. While this sort of climate change does not incur the kind of expenses that the Gulf states and California are suffering, there is still a substantial cost to our local infrastructure.

Unfortunately it is only going to get worse. For many of us this will be manifested in much higher insurance costs as companies are raising premiums to meet these billion dollar claim events.

There are some (dubious) benefits to warmer weather. As I mentioned in an earlier column, the water temperature at the Gap has been running as high as 21C since early July. The windstorm of the 29th mixed the water up pretty well, but it still ended the month at 18C. 

To all my readers, stay safe!