Is it possible to have rain without visible clouds?

As far as I know, clouds are liquid water and eventually the liquid water in them falls down, producing rain. Therefore one would expect clouds before rain.

But is it theoretically possible to have rain when there aren't any visible clouds? Maybe if the concentration of liquid water in the air isn't too high it is possible.

up vote 4 down vote accepted

I actually witnessed this in Ashland, OR several years ago. A strong winter storm had just passed when there was a sudden, brief downpour. When I looked up, there was not a cloud in the sky. What I believe happened is that the air was supersaturated with moisture when a brief breeze caused water to condensate around the few nuclei available. This seems to be confirmed by the second scenario in this explanation:

Consider the very rare situation in which still air is supersaturated with moisture (its relative humidity is above 100 percent) and clouds have not formed because condensation nuclei are practically nonexistent. Water vapor will quickly condense onto the few nuclei that are present and the droplets will rapidly grow into raindrops.

This is the one and only time I have ever experienced this.

Yes We have them all the time they are called sun showers Wind can push rain miles from the clouds that it falls from.

  • 1
    Always I've experienced sun showers, there were clouds. They were sun showers because there weren't clouds in the direction where the sun was, although there were clouds in the direction rain came from. As far as I can remember, I've always seen sun showers in the afternoon, when the sun low and clouds were high in the sky. – Pere Jun 28 '17 at 15:41
  • That's all anecdotal, sun showers only require wind and rain, there need not be any visible clouds, although there will usually clouds nearby, and of course clouds can dissipate while the rain is still falling, since it can take quite a while for rain to reach the ground in windy conditions. – John Nov 24 '17 at 4:21

We have just experienced rain from an almost cloudless sky in Forster Australia at 1230pm Almost no wind at 4 knots. Humidity very high Lasted around 5 minutes with the rain drops increasing in size over the 5 minutes. Nickenter image description here

  • There are clearly visible clouds here (not just the ones in the bottom left hand corner) so I'm not sure this really counts. – bon Jan 1 at 8:51
  • Hi Bon, I intentionally included the little cloud as pictured, its not a rain cloud nor was it responsible for the shower. I have since learnt through the Bureau of Meterology that the phenomenon is a SEREIN which is a French name for rain falling from a cloudless sky. – Nick Minutillo Jan 1 at 20:57

It is possible for a cloud to rain itself out. But it then takes some time for the rain to fall to the ground. By the time the rain reaches the ground, the cloud is no longer there. This is rare, but it can happen.

This is absolutely possible, I was cycling my bike in a completely cloudless sky when I suddenly hit this wall of super humid and hot air. I had never experienced this kind of air before. As I passed into this wall of humid air, it started raining. I guess at 100% humidity, you only need a slight drop in temperature for the water to start falling out of the air.

Your Answer

 
discard

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Not the answer you're looking for? Browse other questions tagged or ask your own question.