Well, we’re starting to get into the weather patterns where we can predict impending frosts. There’s a lot of gardeners that think frost is this super mysterious thing, knowable only by trained meteorologists. We like to teach people about it, because truly, observation is the only tool you typically need!
All of you are familiar with fog, you’ve seen it many times. But, what you might not appreciate is that fog is the exact same thing as frost, just that it hasn’t frozen yet! When this fog freezes, that moisture essentially becomes frost.
There’s this meteorological term you’ve likely heard of, but might not know what it means. It’s called the dew point. This is the air temperature at which air can no longer hold any more moisture, which essentially causes that humidity to become water vapor. This vapor occurs when the air temperature drops below the dew point. When it’s above freezing, it becomes fog. When it’s freezing, this vapor becomes frost.
The reason you might not know “dew point” like you do other environmental things like humidity or temperature is because it’s only regularly used in rather niche circles. For example, the dew point is how pilots assess the risk of freezing when landing, thus determining whether they should flip their heater switches on to prevent ice buildup. Another key use is frost prediction!
Warmer temperature air can hold a lot more moisture. This is why fog is not particularly common in the warmer months. But, when temperatures start dipping, the air can’t hold nearly as much moisture. Cooler temperatures also make it much more likely that temperatures will fall below the dew point, thus making fog or frost occur more frequently.
As you can see, we’re getting strong fog in the mornings these days. All it takes is near freezing temperatures and boom, we’ll have some serious frosts.
Gardening has probably brought us to the point of being “amateur meteorologists.” Especially in the shoulder seasons, it’s important to observe what’s going on as your harvests can depend upon it. People are perhaps fascinated by our ability to “predict frosts” and impending winter. But, like anything, it’s really just about understanding principles and the nature of the environment.
We’re expecting “the turn” very soon. Temperatures look to be dipping into the 20’s next week for us, so we’re definitely looking to play the garden end game in short order. At a certain point, it’s not about whether the plants survive and more about how much we want to be gardening in freezing temperatures.
Where there’s frost, there’s potential for snow. We love the quip, “Alaskan’s live like there’s snow tomorrow!” It’s coming. And sooner than we’d hope!
