Peter, this Sempervivum 'Sha'uri' is stunning.

unfortunately this colour doesn't come out every year

Spectacular color!!

Peter, what kind of conditons tend to bring that intensity of color?

a lot of dry sun in the early spring - rain only once a week for 1-2 hours;

that's the weather we had in 2008 in north-germany

That is what seems to bring the best spring colors here also.
Do you get much snow?

not in that year; in 2008 the temperatures were gentle the whole winter and there was nearly no snow;

in the last 3 years we had a lot of snow until april; the temperatures came down to -20 Grad Celsius; and the spring-sun came later and lower...

Wow, that is really cold, for us that would be -4°F. Very cold indeed. I think our lowest this winter was in the high teens, -7C for you.

We had one of our wettest spring on record this year, and no snow at all during the winter. It has been very different weather this entire year.

semps and jovis love a big snow cover; last winter we had about 1 m on top of them; then they tolerate each temperature;

the winter before last we had -25 Grad Celsius without any snow and the week before thawing.....it cost me around 400 pots of semps :-(

but one year later all holes were stuffed

That would be heart wrenching. So glad you did not seem to lose entire varieties. You must be close to mountains?
My altitude is a little over 300 feet, or about 92 m.
Our winters are usually pretty mild.

I'm closed to the coast and there is no higher hill then 250 m all around ;-)

if you search for "Rostock/Germany" on Google Maps - that's near by to me;

So no high mountains.
I looked it up, what a beautiful place. I love the buildings and rows of homes.