Olympic National Park is defined by remarkable diversity created by a wide range of precipitation and elevation. Encompassing nearly a million acres, it preserves a vast wilderness, thousands of years of human history, and several distinct ecosystems, including glacier-capped mountains, old-growth temperate rain forests, and more than 70 miles of wild coastline. Summers are generally fair and warm, with high temperatures between 65 and 75 degrees F, and July, August, and September are the driest months, while the rest of the year brings heavier precipitation. Winters are mild at lower elevations, but snowfall can be heavy in the mountains, and different weather conditions commonly exist within the park at the same time.