Wyoming Weather by Month

The Short Answer

Wyoming is a four-season state with serious altitude, and the difference between a valley at 4,000 feet and a mountain pass at 9,500 feet can be 25 degrees on the same afternoon. Jackson Hole sits at about 6,200 feet. Cheyenne is at 6,063 feet. Lander, in the Wind River Basin, is lower at around 5,400 feet and noticeably warmer in summer. These numbers matter because most travelers are moving between multiple elevations in a single day.

The table below uses Jackson Hole as the primary reference since it anchors so many Wyoming trips, but note that the Bighorn Basin around Cody and Thermopolis runs 5 to 10 degrees warmer on summer days, and the high Wind River Range sees snow every month of the year.

Spring: March Through May

March through May is Wyoming's most variable stretch. At lower elevations like Cheyenne (6,063 feet), March days can reach the low 50s, but storms push through the plains with 40 to 50 mph gusts that make 45°F feel brutal. In the mountains, spring means a lot of snow. Jackson Hole Mountain Resort typically runs through mid-April, and heavy snowfalls in March and April are normal. If you're planning a ski trip, late February through mid-March is usually more reliable than the back half of March.

April is mud season in much of the state. The high trails in Grand Teton and the Wind River Range are buried, river levels are rising with snowmelt, and the dirt roads that serve ranches and backcountry areas become impassable. Yellowstone's North Entrance at Gardiner, Montana stays open year-round, but the other routes begin opening in phases from mid-April. The road from Mammoth to Norris typically opens first. Check the NPS Yellowstone road status page the week before you go because dates shift year to year depending on snowpack.

May is when the state genuinely wakes up. The inner Teton Park Road, the scenic route from Moose Junction past Jenny Lake to String Lake, typically opens to cars in the third week of May. The Beartooth Highway (US-212), which crests at 10,947 feet above sea level between Cody and Red Lodge, Montana, usually clears by Memorial Day weekend and is worth the detour if you're coming from the east. Snow is still possible at elevation well into May, and morning temps in Jackson will flirt with freezing through the end of the month. Pack layers even if the forecast looks warm.

Summer: June Through August

June through August is the main visitor window and the only time everything is open at once. In the Jackson Hole valley, July afternoons average around 84°F, but nights cool to the mid-40s, so you will want layers for early morning wildlife drives along the Teton Park Road. The Bighorn Basin around Cody and Thermopolis runs noticeably hotter: summer highs regularly hit 90°F or above in July and August, and Lander in the Wind River Basin is similarly warm. By contrast, the high plateaus inside Yellowstone sit at 7,000 to 8,000 feet and stay 10 to 15 degrees cooler than the valley towns on summer afternoons.

Plan for afternoon thunderstorms from late June through August, especially in the mountains. These are not optional background weather events. A clear morning in the Wind River Range or on a Yellowstone geyser basin can turn to lightning in an hour. Start hikes early and be off exposed ridges by 1 or 2 in the afternoon. Wildfire smoke can drift in from Idaho and Montana during dry stretches in late July and August, occasionally limiting visibility for a few days at a time. It is not guaranteed every summer, but it happens often enough to factor in if air quality is a concern.

Crowds peak in July and the first half of August. The South Entrance to Yellowstone via Flagg Ranch, inside the John D. Rockefeller Jr. Memorial Parkway, can back up an hour or more on summer weekday mornings. The East Entrance from Cody sees similar pressure. If you're flexible, early June and mid-to-late August offer the same open roads with noticeably fewer people. For a full breakdown of which weeks work best for specific interests, see the Best Time to Visit Wyoming guide.

Fall: September and October

September is the most underrated month in Wyoming. Crowds thin sharply after Labor Day, lodging rates drop across the state, and the elk rut begins around mid-September. Bulls are bugling in Grand Teton's Elk Ranch Flats and along the edges of the National Elk Refuge south of Jackson by the third week of the month, and you can hear them from the road at dawn. Afternoon highs in Jackson run around 70°F in early September and drop into the upper 50s by the end of the month. The aspens along the Gros Ventre Road and along US-26/287 over Togwotee Pass turn gold from late September into early October. The Jackson Hole and Tetons region in fall is a different trip than the summer version, and a lot of people prefer it.

October brings the first serious snows. Mountain passes can close on short notice, sometimes overnight, and the inner section of the Teton Park Road from Moose to Jenny Lake typically closes to cars by late October. The Chief Joseph Scenic Byway (Wyoming Highway 296), one of the most dramatic roads in the state with direct views toward the Absaroka Range, closes for winter around late October or November. The Beartooth Highway shuts down for the season sometime in October. Cody stays accessible year-round via US-14/16/20, but the 52-mile drive from Cody to Yellowstone's East Entrance closes when the park closes that road, typically in early November.

Winter: November Through February

Yellowstone closes to wheeled vehicles at most entrances in early November and does not reopen until mid-April. But winter is not a quiet season in Wyoming. Jackson Hole Mountain Resort typically opens in late November or early December, and Grand Targhee Resort, on the west slope of the Tetons above Alta, runs through mid-April. Snow King Mountain in the town of Jackson is walkable from downtown and opens on a similar timeline. Between the three resorts, the Jackson area gets more ski traffic in January and February than at any other time of year.

Temperatures in Jackson Hole in January average a high of 28°F and a low of 6°F, with cold snaps dropping to minus 20°F or colder during inversions, when the valley traps cold air for days at a stretch under a clear cap. Cody and Thermopolis in the Bighorn Basin run 10 to 15 degrees warmer than Jackson in winter because of lower elevation and fewer inversions. Cheyenne on the plains sees wind more than deep cold, with January highs around 38°F but brutal gusts that drive wind chills well below zero. Wind is a constant on the I-80 and I-25 corridors.

Yellowstone in winter is accessible by snowmobile or guided snowcoach from the West Entrance at West Yellowstone, Montana, or the North Entrance at Gardiner. The oversnow season typically runs mid-December through early March. If you're driving into Wyoming between December and February, check road conditions through the Wyoming Department of Transportation at 511.wyo.gov before tackling any mountain route. US-26/287 over Togwotee Pass and WY-22 over Teton Pass both close periodically and require chains or four-wheel drive after storms. For help sorting out your arrival, see Wyoming Airports and Getting There and Getting Around Wyoming.

Practical Tips for Planning Around Wyoming Weather

Check 511.wyo.gov before driving any mountain route from October through May. Roads can go from clear to chain-required or closed in under an hour during a storm. This applies to Teton Pass (WY-22), Togwotee Pass (US-26/287), the Bighorn Scenic Byway (US-14 Alt), and the passes through the Snowy Range above Laramie. Even in late June, an unexpected storm can briefly shut a high pass.

Layers are non-negotiable in any season. A July afternoon in Cody might hit 92°F, but the same evening at a campsite near Jenny Lake might drop to 38°F. Wool or synthetic base layers, a wind layer, and a real insulating layer belong in your bag regardless of the month. Rain gear is worth carrying from May through September. See the companion guide to what to pack on the Wyoming Travel Guide homepage.

For the broader planning picture, including which months line up best with the national parks, elk season, or ski season, read the Best Time to Visit Wyoming guide. If you're working out which part of the state to base in, the Jackson Hole and Tetons region page covers the northwest corner in detail, and the regional overview on the homepage connects you to the other five regions.