Top News

The Journal Pioneer

CINDY DAY: Seasonal lag can be a drag

By the time the next solstice rolls around, our daylight hours will average only about 9 hours across the region.
By the time the next solstice rolls around, our daylight hours will average only about 9 hours across the region.

The summer solstice has come and gone. The daylight hours are dwindling… ever so slowly, but they are.

Let’s compare the daylight hours last Friday – the longest day of the year – with today’s hours of daylight:

Isn’t it a shame that the longer days don’t coincide with the warmest weather? As it turns out, the oceans and lakes we all like to visit for our long-awaited summer vacations are a big part of why that is.

On Friday, the longest day of the year, the sun’s rays were the most direct at the Tropic of Cancer and the amount of incoming solar energy, or radiation, was at its highest. However, bodies of water around us are still very chilly. Water takes much longer to heat up than land. Since our planet is about 70 per cent water, the temperatures on land are highly dependent on the temperatures of the bodies of water that surround us.

phenomenon is called seasonal lag. It’s the reason the date of maximum average air temperature is delayed until sometime after the date of maximum insolation. Insolation is a fancy way of saying the amount of sunshine that reaches an area.

In Atlantic Canada the seasonal lag is consistent both in summer and winter; August is the warmest month and February is the coldest.

Now I apologize if this gives you a little seasonal lag but … six months from today will be Christmas Day and since we’ve gone there, the day lengths will range from 7 hours and 35 minutes in Labrador City to 8 hours and 48 minutes in Halifax!



Cindy Day is the chief meteorologist for SaltWire Network.


On a scale of 1-10, how likely are you to recommend the Journal Pioneer?


Recent Stories