Thinking of heading to Wyoming around Memorial Day? You’ll need to get ready for a bit of everything—spring blending into early summer. Days usually feel pretty mild, with highs anywhere from the 50s to 70s, but don’t be surprised if the nights still get close to freezing, especially up in the mountains. Cool mornings, comfortable afternoons, and sudden shifts in weather are all on the table.
This time of year, melting snow is common, so you might deal with wet ground or the occasional spring shower. Some spots still have snow patches, while others are already greening up. The mix keeps things interesting, but it means you’ll want to pack for warmth and chillier temps.
If you’re hoping for fewer crowds than summer but still want decent weather, Memorial Day really strikes a nice balance. You get longer daylight hours and a better shot at open roads and trails, though some higher passes could still be closed. That unpredictability is just part of Wyoming’s charm in late May.
Typical Memorial Day Weather in Wyoming
Late May usually brings mild days, cooler nights, and the occasional spring storm. You’ll notice big temperature swings, clear starts to the day, and a real chance of afternoon showers or thunderstorms, especially up high.
Average High and Low Temperatures
Around Memorial Day, daytime highs in much of Wyoming usually fall in the mid-60s to mid-70s °F (18–24 °C) range. Lower spots like Cheyenne or Casper warm up more, while mountain towns like Jackson or Yellowstone stay cooler.
At night, it often drops into the upper 30s to mid-40s °F (3–7 °C). In the valleys and higher terrain, it can get close to freezing. Layering makes a big difference, since mornings might feel chilly even after a warm afternoon.
Camping or hiking? Get ready for some cold overnights. It’s pretty normal to see a 30-degree swing between day and night across the state.
Daytime and Nighttime Conditions
Mornings tend to be calmest, with clearer skies and light winds. As the sun climbs, scattered showers or thunderstorms start to pop up, especially in central and western regions.
Afternoons can feel warm in the sun, but clouds build fast. Quick rain showers might roll in, bringing gusty winds or a sudden chill.
At night, skies usually clear again, so temperatures drop. In many places, you’ll notice crisp air and a real chill after sunset. The mountains exaggerate this, since melting snow cools the air even more.
Weather Patterns Across the State
Wyoming’s weather really depends on where you are. In the eastern plains, Memorial Day usually means drier weather but a bigger risk of thunderstorms or even tornadoes. Winds hit harder here than in other areas.
In the mountainous west—think Yellowstone and Grand Teton—snow patches are still around. Rain and cool temps show up more often, and spring runoff can make trails muddy.
The central basins sit somewhere in between. You get warmer days, cool nights, and still a risk of afternoon storms. All this variety means the weather’s a bit unpredictable, so you’ll want to stay ready.
Precipitation and Rainfall Trends
Late May brings unsettled weather to Wyoming. You’ll see a mix of dry stretches and passing showers, with rainfall jumping around depending on where you are. Snow can still show up in the high country, while lower valleys mostly get rain.
Chance of Rain and Showers
Memorial Day bumps up your odds for measurable precipitation compared to early spring. In Cheyenne, there are about 8 days with precipitation in May; Jackson averages closer to 9 days.
Showers usually hit in the afternoon, triggered by daytime heating. Thunderstorms are common, especially out east. They can bring heavy rain, small hail, and gusty winds.
Plan for variable skies. Mornings are often drier, but afternoons carry a higher risk of showers. If you’re outdoors, rain gear is a smart move—especially in the mountains or open plains.
Average Monthly Rainfall
May’s one of Wyoming’s wetter months. Cheyenne averages about 1.8 inches of rain in May; Jackson gets about 1.7 inches. That’s noticeably wetter than March or April.
Rain doesn’t fall evenly. Some days are bone dry, then a single storm might dump a big chunk of the monthly total. Wyoming’s May rain comes from frontal systems and mountain thunderstorms, not the summer monsoons you see farther south.
Snow at lower elevations is rare by now, but up high, mountain passes might still get light accumulations. If you’re crossing high ground, wet snow or slush can still surprise you.
Regional Precipitation Variations
Wyoming’s landscape creates big differences in rainfall. The western mountains, like the Tetons and Wind River Range, get more rain thanks to elevation and orographic lift. Jackson averages more wet days than the plains.
Central basins and eastern plains stay drier overall, but storms there can pack a punch when they do arrive. Cheyenne often gets fast-moving thunderstorms that dump heavy rain in a hurry.
If you’re traveling, expect wetter weather up northwest and drier stretches in central Wyoming. The eastern border near Nebraska and Colorado sees more thunderstorm action than interior valleys.
Snowfall and Late Spring Weather Events
Late May in Wyoming mixes mild spring days with a bit of lingering winter. Most days feel pretty comfortable, but snow can still show up, especially in the mountains, and storms might mess with your plans.
Likelihood of Snow in Late May
Snowfall drops off by Memorial Day, but it doesn’t vanish. In places like Cheyenne, late May snow is rare, with lows above freezing and highs in the upper 50s to 60s °F (13–20 °C).
Higher elevations are a different story. Jackson and the Tetons can still pick up late-season snow, sometimes a few inches at once.
Cold fronts sweeping across the Rockies can cause sudden temperature drops. You might get a warm afternoon followed by wet snow or a rain-snow mix overnight.
Thunderstorms bring more variety. Most just drop rain, but some include hail or brief snow showers if it gets cold enough.
Mountain vs. Plains Snowfall
The split between mountains and plains shows up in late May. On the plains—think Casper or Cheyenne—snow is usually light and melts fast since the ground’s warm.
Mountains are another matter. Jackson, Yellowstone, and the Wind River Range can still get heavy snow. Jackson’s average May snowfall is about 20 mm (nearly 1 inch water equivalent)—that can mean several inches of snow.
Elevation makes the biggest difference. Spots above 8,000 feet often stay snowy into June. Trails and passes can be buried, even if nearby valleys look green.
So, you might hike through springtime on the plains while the high country still has a solid snowpack.
Impact on Travel Plans
Snow and late spring storms can throw off your travel plans in Wyoming. Mountain roads like Teton Pass or Beartooth Highway might still be closed or delayed for snow removal. Even open roads can get slick in the morning if temps dip below freezing.
If you’re camping or hiking, expect muddy valleys and snow lingering up high. Bring waterproof gear and plenty of layers.
For road trips, check weather forecasts and Wyoming Department of Transportation updates before you go. Sudden snow squalls aren’t as common as in winter, but they can still cut visibility.
Flights don’t get delayed as much by late May snow, but Jackson Hole Airport sometimes sees holdups if storms sweep through the Tetons.
Sunshine and Daylight Hours
Late May brings long days and a decent amount of sunshine to Wyoming, but clouds and spring storms still show up pretty often. You’ll see a mix—some bright, clear days and then patches of clouds that move in fast thanks to the high elevation and wide-open spaces.
Average Hours of Sunlight
By Memorial Day, you get close to 14.5–15 hours of daylight across most of Wyoming. Sunrise comes before 6:00 a.m., and sunset often pushes past 8:30 p.m.
Actual sunshine hours shift by location. Here’s a quick look:
| City | Avg. Daylight (hrs) | Est. Sunshine (hrs) |
|---|---|---|
| Cheyenne | ~14.6 | 9–10 |
| Jackson | ~14.8 | 8–9 |
| Sheridan | ~14.7 | 9–10 |
Higher elevations, like Jackson and the Tetons, get a bit less direct sun due to mountain clouds. Lower valleys and plains usually see longer clear stretches once morning clouds fade.
Cloud Cover and Clear Skies
Cloud cover in late May jumps around. Mornings might start with scattered clouds, then skies clear up by afternoon. Still, spring thunderstorms can form fast, especially out east and near the mountains.
On average, Wyoming sees 60–70% of days with at least partial sun this time of year. Clear-sky days—where clouds cover less than a third of the sky—are pretty common, but you’ll also get days with mixed sun and cloud.
Planning outdoor stuff? Expect a mix: several hours of bright sun most days, but some shade from passing clouds too. Bring layers and sunblock, since UV levels stay strong even when it’s partly cloudy.
Wind and Humidity Levels
Late May usually brings breezy afternoons and dry air to Wyoming. Wind is a constant, while humidity stays low enough to keep things comfy during the day but cooler at night.
Typical Wind Speeds
Wyoming ranks as one of the windiest states, and Memorial Day fits the trend. Average wind speeds run from 12 to 20 mph, with stronger gusts on the open plains and near mountain passes.
The most persistent winds blow from the west to northwest, shaped by the high plains and mountain ranges. Gusts sometimes reach 30 to 40 mph, especially around Cheyenne and Laramie.
Winds start light in the morning and pick up by midday. By late afternoon, gusts are more frequent, and they can make it feel cooler than the thermometer says.
If you’re camping or hiking, make sure to secure tents and gear—sudden gusts happen a lot. Drivers on highways should stay alert, since crosswinds hit hardest on exposed roads like Interstate 80.
Humidity and Comfort Levels
Wyoming usually has lower relative humidity than a lot of other states, especially once late spring rolls around. During the hottest part of the day, humidity drops to about 25–35%. At night, it climbs up closer to 60–70%.
This big swing means afternoons feel dry and comfortable. Once the sun goes down, evenings cool off fast.
You’ll probably want a jacket or an extra layer after dark, even if it felt toasty earlier.
Dry air speeds up evaporation, so you might notice you get thirsty faster than usual. Remember to drink water often, especially if you’re hiking or doing anything active outside.
You won’t have to worry about sticky or muggy air like in more humid places. Instead, the air feels crisp, and the skies usually stay clear. The strong sunshine just adds to that dry feeling.
Travel Tips for Memorial Day in Wyoming
Wyoming weather around Memorial Day can flip from mild sunshine to cold rain or even snow up in the mountains. If you’re ready for these changes, you’ll stay comfortable and safe, whether you’re camping, hiking, or just driving through.
Packing Recommendations
Bring layered clothing because temperatures can go from the 30s in the morning to the 60s later on. A light base layer, an insulating fleece, and a waterproof shell work well together.
Always toss in rain gear like a waterproof jacket and pants. Afternoon showers show up a lot, and wind can make it feel even colder.
Footwear matters. Grab waterproof hiking boots with good grip for muddy trails. If you’re camping, pack a cold-weather sleeping bag, since nights can get chilly—sometimes even below freezing in the mountains.
Other handy things to bring:
- Gloves and hats for extra warmth
- Sunscreen and sunglasses for that high-altitude sun
- Reusable water bottles so you don’t get dehydrated
Driving and Outdoor Activities
Road conditions can shift fast. Rain sometimes turns to snow at higher elevations, especially near Yellowstone or the Tetons. Try to keep your gas tank at least half full because fuel stops can be few and far between out there.
If you want to hike or fish, get an early start. Storms tend to roll in during the afternoon. Trails might be muddy, so give yourself extra time and wear the right boots.
Camping’s super popular and campgrounds fill up fast. Reserve a spot if you can. If you’re winging it, check out less crowded places like the Bighorn Mountains or Flaming Gorge.
When you’re watching wildlife, keep your distance. Bison, elk, and moose get pretty active in spring, and you never know when one might appear along a road or trail.
Weather-Related Safety Precautions
Before you head out, check those forecast updates. Mountain weather can take a turn for the worse in less than an hour, and honestly, it catches people off guard all the time. Bring a weather radio, or use mobile alerts if you’ve got service.
Spring storms bring real lightning risks. If you hear thunder, get down from those high ridges, and look for shelter in a building or vehicle if you can. Open fields and lone tall trees? Yeah, steer clear of those.
Rivers and streams get wild with snowmelt. Water rises fast, and currents get strong. Even if it looks shallow, crossing can still be risky.
Nights can get colder than you’d expect. If you end up wet and the temperature drops, hypothermia becomes a real concern. Stash dry clothes in a sealed bag, and skip cotton since it just hangs onto moisture.