Thunderstorms are probably the most prominent objective hazard in alpine climbing. However, fog can also become a serious problem. If you are on well-developed and marked trails, fog is not a real danger for further orientation. However, if you are on the approach to the wall without markings, already on the wall or on the descent without markings, poor visibility can quickly become dangerous, as you can quite easily lose your orientation. On the other hand, fog is usually not so bad in very well protected routes, where there is a bolt every few meters, because you can orient yourself by the many bolts. However, if you are on a less well-protected alpine route where a piton comes only once in a while, good visibility plays a crucial role for wall orientation.
In addition to fog, temperature fluctuations can also get climbers into trouble. If a person climbs a sunlit wall, which is in the shade from midday, this can be very pleasant at first in high summer. In this case, it is important to drink enough and apply sunscreen appropriately, as the sun becomes more aggressive with increasing altitude. With the climbing helmet, the head is protected from the sun. In walls where it can get cold quickly due to the lack of sunlight, especially if the wind is also blowing strongly (so-called wind-chill effect), you should always have an insulating jacket with you to avoid getting cold. This may be necessary especially at belay stations, where you often have to wait for some time with little movement.
While rappelling, strong winds can also blow the ropes all over, so that they can get stuck somewhere and cannot be pulled. Depending on your individual condition, strong winds can also hit your psyche when the roaring wind hits your ears, and you are currently in an extremely exposed climb.
Another factor that can quickly make a route seem significantly more challenging or even impossible is wet rock. After prolonged rainfall, cracks, dihedrals and walls with many grass ledges or bushes dry very slowly. Thus, the drying time takes much longer than in slabs or on exposed pillars. Thus, wet rock can quickly turn a mandatory climbing section into an insurmountable spot.