A large glacial complex covers a major portion of Olympus's slopes and is the most significant force in shaping its contours. Climbing is possible as soon as the snow firms and can be easily walked over. This can be as early as April. Late June through early September are generally the best months in terms of weather to make the climb. Trail travel in June may be slow until muddy sections dry out and crews repair washouts.
Rock fall on the summit block makes a hard hat advisable.
Olympus is a major glacial mountain and can be climbed safely only by persons experienced in correct climbing techniques. Falling into a hidden crevasse is the major hazard and practice in crevasse rescue technique is essential. At times when the snow surface turns very icy, long falls on glaciers are an additional danger. Foul weather can also trap a party on exposed parts of the mountain. For safety, inexperienced people are referred to local guides, climbing schools and climbing books.