Stratus Clouds: What Are They, and How Do We Define Them?

There are all sorts of clouds in our atmosphere: from the infamous cumulus and nimbus to the alto and cirrus. But have you ever heard of a stratus cloud?

Stick with us to learn more about these fascinating clouds, including how they’re formed and defined and the weather they produce. 

Stratus Clouds What Are They, and How Do We Define Them

What is a Stratus Cloud? 

Picture this: a city skyline clouded in a blanket of low-lying fog. It’s an eerie phenomenon that many of us have seen, and those clouds responsible for that low-lying fog are usually the stratus.

Stratus clouds are often described as blanket clouds because they sit low to the ground. Sometimes, they may even touch the ground. 

There are two species of stratus cloud: nebulosus and fractus. A stratus nebulosus is one of the species of a low-lying stratus cloud.

These clouds are often described as featureless and even dull – they have no actual shape to them, and they’re usually highly opaque and thin, especially when they sit close to the ground. 

The other species of stratus cloud is a stratus fractus. These clouds may also be featureless like the nebulosus, but they may have slightly more shape and can sometimes be thicker.

You may often see these clouds hovering around mountains and the tops of buildings, and they can appear to be ragged or fragmented. 

Depending on the conditions of your environment, stratus clouds may mask the sun. Sometimes though, the sun can still be observed through the clouds.

This is because there are two varieties of these clouds: the opacus cloud variety and the translucidus cloud variety. These terms are as self-explanatory as they sound.

With the opacus cloud variety, the sun may be masked. If a stratus is of the translucidus variety, you may still be able to see the sun through it. Also see ‘Can You Tan on a Cloudy Day? Understanding the Science Behind Tanning and Weather‘.

Stratus Clouds What Are They, and How Do We Define Them

Facts About the Stratus Cloud 

Now, let’s explore some of the most interesting facts about the stratus cloud. 

  • Stratus is often abbreviated to St
  • The Latin term for Stratus is Strato, which means layer 
  • The altitude and height of the stratus cloud is around 0-2km
  • The etage (or cloud level) of the Stratus is low 

Stratus Color

The stratus cloud varies in color but is usually either light or dark gray. 

Stratus Potential for Precipitation

The stratus will rarely cause precipitation. 

Frequency and Cover

In terms of sky cover, the stratus offers cloudy to mostly cloudy conditions. These clouds are among the most common variations. 

Species of Stratus

There are two main species of stratus. These are stratus fractus and stratus nebulosus. The fractus species appears ragged and fragmented in the sky, while the nebulosus is often transparent and filled with vapor but lacking in detail. 

Varieties of the Stratus Cloud 

There are also three varieties of stratus. These are stratus opacus, stratus translucidus, and stratus undulatus. Opacus will block out the sun, translucidus will show the sun through the cloud lover, and undulates can be described as having a wave-like appearance. 

Similar Clouds to the Stratus 

Clouds similar to stratus can include altostratus, stratocumulus, and nimbostratus clouds

Altostratus is usually higher in altitude than the stratus, so they won’t come into close contact with the ground. Altostratus clouds also offer more visibility. 

Stratocumulus clouds can be observed at the same altitude. However, stratocumulus will often have more features than the stratus. This could include more color and shape. 

The nimbostratus is also observed at the same altitude as the stratus, and both clouds are featureless and share similar colors. However, the nimbostratus will often bring rain with it.

So, if there’s no rain where you are, you’re probably looking at a stratus rather than a nimbostratus.

Final Thoughts

The stratus is one of ten major cloud types. It’s also one of the most common clouds you’ll see in the sky. So, next time you find yourself beneath a blanket of cloud cover, look up to the sky and see whether a stratus cloud is causing your cloudy day! 

Remember: if there’s no rain, it’s stratus. If you’ve got some precipitation, you’re looking at a nimbostratus! 

Andrew Capper