‘As the days lengthen, the cold strengthens’
I am not one of those people who count down to the arrival of spring. Doing that can be disappointing.
How many times have we made it to mid February relatively unscathed, only to have our hearts broken in March? Not only can we get our worst storms late in the season, but it’s not uncommon to experience bitter cold as well. I love winter so I have no qualms about the cold.
Many people falsely believe that once the days start to grow longer, the temperatures begin to rise. Grandma knew better. She used to say: "As the days lengthen, the cold strengthens.”
Grandma had observed this to be true. It's also scientifically correct, but why? After all, we receive the least amount of daylight on or around Dec. 21. As the daylight minutes grow, shouldn’t it get warmer?
Not really - at least not right away.
The reason is “seasonal lag” which is the phenomenon where the date of minimum average temperature at a geographical location is delayed until sometime after the date of minimum insolation or daylight. This also applies in the summer when the maximum average air temperature is delayed until sometime after the longest day of the year.
Earth’s seasonal lag is largely caused by the presence of large amounts of water. It takes longer to warm those large bodies of water; conversely, it takes longer for them to cool too.
The difference is not seasonally symmetric; meaning the time between the winter solstice and the coldest period is not the same, as between the summer solstice and the hottest time. In mid-latitude continental climates, that difference used to be approximately 20 to 25 days in winter and 25 to 35 days in summer. Case in point: our winter is just getting started!
Did you know that we are enjoying almost 90 minutes more daylight than we were on Christmas Day? But don’t be fooled by the sunshine, it’s a cold one out there!