As I said before, the temperature on the Teide Mountain are a lot colder than the coast.
During winter it is very easy to find snow, even in big amount, and ice on the roads.
It is advisable, in case of doubts to contact the visitor center (+34 922922371) to make sure it is possible to drive along the whole itinerary and to prefer the central hours of the day when the sun have melted the ice on the asphalt.
In case of cold temperature be also very careful stepping into the visitor center, the day I visited they were washing the windows and the water dripped on the pavement and transformed it in a ice skating ring....
I have often seen this sign, and considered it a bit of an idle warning. However in Teide, it is worth taking a bit more care! The roads g through lots of areas where there are big piles of loose rock. No one is quite sure whether it will come down. There are also steep drops in some places with no crash barriers, so if you had to swerve to avoid any falling rocks, it wouldn't be a nice result even if you managed to miss them.
That's not to say that all of the park is like this, but some bits are a bit dodgy, so drive more slowly and keep your eyes on the road!
I have to admit that as I watched these park rangers trying to move this big rock with their jeep and a very thin rope, I did not give them much chance!
Sure enough there was a big ping and the rope snapped and there were some very sheepish looking park rangers.
When I asked why they were attempting to move the rock, it turned out that they had got fed up with visitors pretending to be Carlos Sainz (a Spanish rally car driver) and performing power slides in the loose lava in the park. They were attempting to block any entrance by moving rocks in the way.
Anyhow they did give up on that rock and started moving smaller ones. I guess the warning here is that if you are tempted to go off road to skid your jeep about in the park, then Don't!
As mentioned already, Mount Teide is over 3.5 km high (that's well over 2 miles). When you take into consideration that Tenerife is an old world from the Guanche language that means white mountain (it's talking about Mount Teide and referring to the snow on the top of it), you start getting the idea that it could be pretty cold up there!
Regardsless of these facts, it didn't fail to amaze me how many people went up in shorts and t-shirts, including some people that took their kids up in shorts and t-shirts and then wondered why the children whinged and wanted to go back down straight away.
When the wind blows or you are in the shade, it really is cold up there, so make sure you have plenty of warm clothes. It's cold enough to sustain snow pretty much all the year round.
If you have a weak heart, or have problems with your ears, you may want to think twice about taking the cablecar to the top of Mount Teide.
The top of the Mountain is approx 3700m high, and the air definitely feels very thin. I have climbed a mountain 4500m high in Malaysia, and the air felt about as thin as it did at the top of that Mountain, although I had had two days to acclimatise that time which probably made the difference.
You will notice yourself getting out of breath quite easily if you walk fast or try to run. The secret with high altitudes is to take it very steady and not to push too hard when you feel out of breath. Just rest for a few moments before carrying on.
This picture shows a GPS with the coordinates of the peak of the mountain, but the interesting part is the third line which shows the altitude near the peak (11704 feet).
when you are at the top then don't enter the crater.
the vulcano is quite active and just about to blow up and there are toxic fumes in the center of the crater.
you wont wanna go there anyway.
it smells horrible.
Be ware about planning your assent at the right time of year and right time of day. The tempretures vary quite allot on Teide, I hope you find this of help.