Be aware that whatever the season, if you're at a high altitude, the weather can change quickly and dramatically. Temperatures The coldest month in Austria is usually January.
However, while many (but not all) canyons are found offshore from major rivers, subaerial river erosion cannot have been active to the water depths as great as 3000 meters where canyons have been mapped, as it is well established (by many lines of evidence) that sea levels did not fall to those depths.anyons cutting the continental slopes have been found at depths greater than 2 km below sea level. Many submarine canyons continue as submarine channels across continental rise areas and may extend seawards for hundreds of kilometres onto the abyssal plain.
The Grand Canyon from an airplane, with the Colorado River visible. The Grand Canyon is a river valley in the Colorado Plateau that exposes uplifted Proterozoic and Paleozoic strata, and is also one of the 19 distinct physiographic sections of the Colorado Plateau province.