The best time for a Pacific Northwest vacation package depends on which destination you choose.Seattle is busiest in July and June, when average temperatures are around 67°F with highs of 78°F in July, and 61°F with highs of 70°F in June. The Emerald City Comic Con also takes place in March. If you'd prefer fewer crowds, January is quieter, with average temperatures around 40°F and highs of 46°F.Portland sees its highest demand in July and June, with average temperatures around 69°F and highs of 83°F in July, and 62°F with highs of 74°F in June. The Portland Winter Light Festival is held in February, and the Rose Festival in September. For a quieter trip, January is a good option, with average temperatures around 41°F and highs of 47°F.Vancouver is most popular in July and June, when average temperatures are around 65°F with highs of 72°F in July, and 59°F with highs of 65°F in June. The Vancouver International Auto Show runs from March through April, and the Vancouver International Film Festival is in October. If you'd prefer fewer crowds, January is quieter, with average temperatures around 38°F and highs of 42°F.Whistler is busiest in December and February, with average temperatures around 24°F and highs of 30°F in December, and 26°F with highs of 33°F in February. For fewer crowds, consider visiting in October, when average temperatures are around 41°F and highs of 50°F.