Surprisingly, it does not take much for a succulent to get sun burnt!  There are a few reasons why and how your succulent could/would get sun burnt and there are a few things you can do if it does.

It was not that hot and my succulent still got sun burnt!
If you move a succulent into a sunny position from its usual shadier spot there is a very high chance that the leaves will get sun burnt.  Of course there are variables to consider.  Summer sun is a lot stronger than winter sun, so should you move your succulent to a sunnier position in the winter chances are they will enjoy the sun and be fine but should you move your succulent to a sunnier position in late spring or summer the end result could be sun burn.  It really depends on the intensity of the sun.

Aeonium Pinwheel succulent with sun burnt leaves

Aeonium Pinwheel – sun burnt leaves.

My brand new succulent got sun burnt as soon as I put it in the sun!
Keep in mind that succulents grown in nurseries are grown under shade cloth.  This is how all succulents are propagated and grown.  Even a baby succulent offshoot/pup grows in the shade of the parent plant until it is old/strong enough to survive the strong rays of the sun.  So if you purchase a new succulent and put the plant in the sun there is 90% chance that the leaves will get sun burnt.  Every succulent that I buy I put straight into the sun knowing this will happen, but I know that in the end the succulent will be stronger and used to growing in the sun (assuming it a succulent species that likes sun).  It can actually take a few months for the succulent to acclimatise and during this time can look a bit worse for wear but I believe it is worth it.

sun burnt succulent leaves sun burnt echeveria imbricata Sedum succulent with sunburn

Above are a few of my succulents that were sun burnt this summer.

If you do not want your succulent to get sun burnt but ultimately would like your succulent to grow in a full sun position you need to start the plant off in a semi-shaded position and gradually allow the plant to receive more sun (time) as it matures.

My succulent suddenly has sun burnt leaves and I did not move it into the sun?!?!
If you are growing your succulent in a half shade/half sun position and one day (during summer) you find the leaves have sun burn this would probably because it was a very hot day (ie 40c/104F) and the intensity of the sun was stronger than the succulent was used to,  The heat of the sun on these hot summer days will easily burn your succulent’s leaves.

Echevveria with sun burnt leaves

What can I do about my sun burnt succulent?

Leave the burnt leaves on the plant.
There are a few things that you can do about your sun burnt leaves. Sun burnt leaves do not look at all attractive and the first thing you will want to do is to get rid of them.  However, if you are experiencing a heatwave or know there is more hot weather on the way and you are unable to move your succulent to a shadier position (as it may be planted in the ground!) then it is best to leave the sun burnt leaves on the plant.  They will protect/shade the lower leaves on the plant below that did not get sun burnt.

Cut the burnt leaves off the plant.
Yes you can carefully snip out the sun burnt leaves to make the succulent look nice again, this will not be detrimental to the plant.  Usually the leaves that get sun burnt are the outer leaves so they should be fairly easy to access.

If you leave your sun burnt leaves on the plant they will eventually complete their natural cycle and go brown, dry up and drop off the plant in due course.

Will my sun burnt succulent die?
No it will not!  Usually only a few leaves will burn.  The new leaves forming in the centre of the succulent actually look amazingly healthy in comparison.  Conversely, you would expect the new (inner) leaves to be burnt and the older leaves (to the outer edge of the plant) to survive.  This is not the case, the succulent is preparing its new growth for the hotter more intense sun.  The older leaves have not been prepared for these conditions and have not been grown to cope with the sun’s intensity – this is why they burn.

What can I do to prevent sun burn?
You can protect your succulents from sun burn by moving them into the shade when it is a hot day out of the intense heat from the sun.  So either move your pots into the shade for the duration of the heatwave or if they are planted in the garden cover them with some shade cloth.  This will deflect some of the intensity of the sun.