Basics

Grand Teton

Grand Teton National Park is beautiful and accessible year round. Summer (July-August) is high season, when all roads and visitor centers are open and the float season is at its peak. However, this is also the most crowded and expensive time to visit. To avoid the crowds, plan your trip in May-June or September-October. Fall is especially magical because of the beautiful fall colors and more active wildlife. The annual rut (breeding season) for elk and deer takes place during this time. Male elk bugle to signal their dominance and attract females. You may even witness a sparring match between two dominant male elk – truly an incredible sight to behold. The bull moose in the park are also actively searching for females and may at times spar for dominance too. Bears are searching for the berries and any other food source they can find, as they only have a few weeks left to gain the additional fat they will need to survive hibernation. Since so much wildlife is active (and often aggressive) in the fall, be sure to view them from your car, or a safe distance away (100 yards).

Keep in mind that some visitor services are closed Oct-May. Click here for operating hours.

Winter is also a worthwhile time to visit – the snow-covered landscapes are spectacular and winter recreation opportunities abound. The park's main roadways, Highway 89/191 and Highway 26/287, are plowed and open for winter travel from the town of Jackson to Flagg Ranch near Yellowstone National Park's south boundary. Park roads are often snow-covered and icy. Be prepared for winter driving conditions. Much of the Teton Park Road (also called the inner park road) is not open to vehicles during the winter months. Visit the park’s Winter Trip Planner for more details.

Yellowstone

Like Grand Teton, Yellowstone is beautiful year-round. Crowds are at their worst in mid-summer, but this is also when all roads and services are open and the weather is at its best. Winter (mid-Dec to Feb) is much less crowded, offering crystalline landscapes and sightseeing by snowmobile, snow coach, skis or snowshoes. Spring and fall have their own appeal – wildflowers in spring, colorful foliage in fall – but the weather can be unpredictable, with snow a frequent possibility. You may see more animals in the cooler months, as elk and bear tend to go to higher elevations during the summer. Fall is rutting season for elk and deer, while bears are actively searching for food prior to hibernation. Keep in mind that, except for the Albright Visitors Center, which is open all year, most services are closed from Oct to mid-Dec and March to late April. Ranger-led summer programs begin Memorial Day weekend. To experience fewer crowds while still enjoying most services, consider planning your trip in late May or September.

Yellowstone is open every day of the year, but the two main tourist seasons are summer and winter. Most entrances (except the North and North East entrances) close in November while roads are being prepared for the winter season, and again in the late March and early April months to clear the roads for the summer season. If you are planning to visit between October and April be aware that many park roads are closed to wheeled vehicles during this snowy time of year.

Road construction occurs every summer in Yellowstone. Information on closures is available on the NPS website.

Grand Teton

This area has long, cold winters. The first heavy snows fall by November 1 and continue through March; snow and frost are possible during any month.

Mid-April, May, June: Mild days and cool nights alternate with rain and occasional snow. Valley trails are snow covered until late May.

July and August: Warm days and cool nights prevail, with afternoon thundershowers common.

September, October, November
: Sunny days and cold nights alternate with rain and occasional snow storms.

December through mid-April: Between storms the days are sunny and nights are very cold. Snow blankets the mountains and valley. Vehicles with four-wheel drive or all-weather tires are recommended for winter travel; roads may be closed during blizzards. Drive at or below posted speed limits at all times; moose and other wildlife are often seen crossing roads during the winter.

Recommended Clothing: Rain gear is recommended during spring, summer and fall. Sub-zero temperatures are common throughout winter and demand multi-layered clothing, hats, mittens and cold weather boots.

Yellowstone

Summer: Daytime temperatures are often in the 70s and occasionally in the 80s in lower elevations. Nights are usually cool and temperatures may drop below freezing at higher elevations. Thunderstorms are common in the afternoons.

Winter: Temperatures often range from zero to 20F throughout the day. Sub-zero temperatures over-night are common. The record low temperature is -66F. Snowfall is highly variable. While the average is 150 inches per year, it is not uncommon for higher elevations to get twice that amount.

Spring and Fall: Daytime temperatures range from the 30s to the 60s with overnight lows in the teens to single digits. Snow is common in the spring and fall with regular accumulations of 12" in a 24 hour period.

Recommended Clothing: At any time of year, be prepared for sudden changes. Unpredictability, more than anything else, characterizes Yellowstone’s weather. Always be equipped with a wide range of clothing options. Be sure to bring a warm jacket and rain gear even in the summer.