What is dew?

Dew is really small

What causes water droplets on the lawn in the morning?  Looking at it, you often wonder if there was rain overnight.  The reality is the weather conditions were perfect for water droplets to form on the blades of grass, on spider webs, or other plants in the late evening, early morning.  This is Dew.

Dew on a dragonfly

Source: Pxhere

Dew only forms under certain weather conditions.  For example, if the previous day was a warm, clear day and the night was cool and clear, then it will form.  Turning liquid into water vapor happens on normal warm days.  The warmth of the sun causes evaporation.  Turning liquid into gas.

Clear, not cloudy nights, hold heat closer to the ground.  Cloudy nights don’t allow the ground to cool off for dew to form.  The warm ground continues to radiate heat into the air with nightfall.  The air cannot hold the moisture if the ground is cool.   Therefore, you will notice dew on grass but not on flower beds.  In short, they keep heat to evaporate the dew.

Are all droplets dew?

Dew on spider web

Source: Pxhere

Dew drops are easily seen on Spiderwebs.  These are sometimes called a dewbow.  But not all moisture drops

are dew.  Some are moisture that couldn’t evaporate from plants so it extracts it into drops called Guttation drops. Guttation drops are excess moisture from the vascular plant that did not evaporate.

In some dry desert areas, certain species of plants including lichen and pine seedlings depend on dew forming to survive.


A temperature that is called the “dew point” is when the water vapor in the air begins to turn back to water faster than the water is evaporating.  Grass, leaves and even car roofs don’t warm up as fast, that is when the dew begins to form. If the temperature gets low in the evening, the dew will freeze to a solid form called “frost.”

Resource: https://dogfoose.com/2014/02/the-dew-point/

Featured Image https://pxhere.com/en/photo/521790

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