Portland's mild climate is best from June through September. Hotels are often filled in July and August, so it's important to book reservations in advance. Spring and fall are also excellent times to visit. The weather usually remains quite good, and the prices for accommodations, transportation, and tours can be lower (and the crowds much smaller) in the most popular destinations. In winter, snow is uncommon in the city but abundant in the nearby mountains, making the region a skier's dream.
Average daytime summer highs are in the 70s; winter temperatures are generally in the 40s. Rainfall varies greatly from one locale to another. In the coastal mountains, for example, 160 inches of rain fall annually, creating temperate rain forests. Portland has an average of only 36 inches of rainfall a year—less than New York, Chicago, or Miami. In winter, however, the rain may never seem to end. More than 75% of Portland's annual precipitation occurs from October through March.