The weather in the Northwest Territories can generally be divided into two different zones – North of the tree line and south of the tree line. The climate north of the tree line is distinctly Arctic - generally very dry, with little precipitation, and cold temperatures. South of the tree line, precipitation is slightly greater, temperatures are warmer, and summer lasts slightly longer – Up to 3 months. As a whole, the NWT experiences some of the world’s longest and coldest winters. No matter when you visit, it's important to be prepared for sudden changes in weather and temperature, especially if you are doing outdoor activities.
Summer is June to mid-August. The temperature can be plus 25 Celsius with the sun blazing around the clock in the far north, where the sun barely sets. This is the best time of year for outdoor adventure. On summer solstice, June 21, the sun doesn't set at the Arctic Circle. The further north one travels, the higher the sun and the longer the season of the midnight sun. Pack shorts and T-shirts, but come prepared with plenty of layering options. On an outdoor excursion, always bring along pants and long sleeves. A hat and gloves can come in handy, and a windbreaker is useful at higher elevations. Brimmed hats, sunglasses and sunscreen protect against the intense summer sun. Good walking shoes are a must. If you're going into the backcountry, consider packing a bug jacket.
Fall is mid-August until October. Temperatures are pleasant for outdoor activity during the day, but drop significantly at night. Bring plenty of light, long-sleeve shirts, sweaters and windbreakers for jaunts around town or in the wilds. Pack a warm hat and gloves, walking shoes, plus waterproof boots.
Winter is long – From mid-October to May. Winters here are cold and snowy, with temperatures dropping as low as minus 45 Celsius at night, and usually remaining below minus 15, even during the day. There is little to no sun at all the further north you travel. This is the perfect time to visit if you are hoping to witness the dancing lights of the Aurora Borealis. A good parka and insulated winter boots are a must. Pack lots of warm clothes and long underwear. Bring wind or snow pants if you have them. Warm hat, gloves or mittens, plus a scarf or neck warmer are essential.
Spring is short and blends easily between winter and summer. This transition season rolls together the last of the winter activities, the arrival of migrating swans, and the rising of the many lakes and rivers. Pack long-sleeved shirts, pants, a windbreaker or shell jacket, sweaters, a warm hat and gloves, plus walking shoes and waterproof boots.