This area is has an undeniable mystical quality, right down to the most unusual weather. Peninsular weather is dominated by the Olympic rain shadow. Simply put, the Olympic mountain range causes the moist sea air to dump its precipitation before crossing the high peaks. That’s why cities directly east of the mountains see 10–17 inches of rain per year, but the western slope of the mountain might see upwards of 160 inches! Three-quarters of the national park’s precipitation falls October–March, and even during the relatively dry months, it’s best to be ready for rain. The geography helps keep temperatures mild, generally ranging from the low 70s in summertime to the mid-40s in the winter.