Stretching across nearly 3,500 square miles in Wyoming, Montana, and Idaho, Yellowstone is not only one of the most popular national parks in the U.S., it is credited as being the first national park in the entire world. Each year, millions of people are drawn to this amazing place to explore the beautiful landscapes, experience unique geological formations, and spot wildlife. But the type of weather you can expect while visiting there is highly dependent on when you go, as Yellowstone is definitely a place where you can experience all four seasons to the fullest, sometimes even in a single day.
Elevation Impacts Climate and Weather
The average elevation of Yellowstone is roughly 8,000 feet (2,400 meters). That means there are sections of the park that sit at both higher and lower altitudes, which will have an impact on weather conditions. Expect temperatures to be warmer and more stable at the lower elevations, and colder as you climb higher. Additionally, the weather conditions can change rapidly in the mountains, warming up and cooling off quickly, or bringing in rain and snow showers when the skies were clear just a short time earlier. Be prepared for those shifting conditions to occur, as they can be a challenge at any time of the year.
Cold temperatures and heavy snowfall abound during the spring, when daytime highs, on average, reach 37 degrees Fahrenheit (3 degrees Celsius) in March and as warm as 51 degrees Fahrenheit (10 degrees Celsius) in May. Overnight temperatures during that same period are usually still well below zero degrees Fahrenheit, ranging from single digit lows in the early part of spring and climbing up to 28 degrees Fahrenheit (-2 degrees Celsius) later in the season. Precipitation typically still comes in the form of snow during this time of year, with an average of 26 inches (66 cm) falling in March, trailing off to just 6 inches (15 cm) in May.
What to pack: Bring plenty of waterproof layers, hats, and gloves.
Unsurprisingly, summer brings the most stable and predictable weather of the year to Yellowstone, with warm days and cool nights. This makes it an excellent time to visit, which is why the park is often very crowded and busy during the months of June, July, and August. During those months, the average daytime temperatures climb into the upper-60s and 70s (18-25 degrees Celsius) making it a pleasant time for hiking, camping, and backpacking. At night, the mercury can still drop into the 30s and 40s (3-5 degrees Celsius) however, so be sure to bring layers to keep you warm. Snowfall is still a possibility, even in the dead of summer, although it doesn't occur all that often. June is the rainiest month of the year however, with 2.2 inches (5.5 cm) of precipitation on average. July and August are a bit drier, with 0.84 inches (2.1 cm) and 1.3 inches (3.3 cm) respectively.
What to pack: Have layers ready and especially some waterproof ones.
Autumn arrives early in Yellowstone, bringing plenty of vibrant colors and cooler weather along with it. The crowds also dissipate rapidly after Labor Day, making it an excellent time to be in the park. Visitors will find that September remains relatively warm and dry, with the average high reaching 62 degrees Fahrenheit (17 degrees Celsius) and the low dropping to 30 degrees Fahrenheit (-1 degree Celsius) at night. Rainfall is also just 1.3 inches (3.8 cm), with the occasional light snow bringing a dusting of fresh powder. By October, those numbers start to shift rapidly however, with the daytime highs reaching 48 degrees Fahrenheit (9 degrees Celsius) and the overnight lows dropping to 22 degrees Fahrenheit (-5 degrees Celsius). November tends to be both cold and wet with the mercury climbing to just 33 degrees Fahrenheit (1 degree Celsius) on average and falling to 11 degrees Fahrenheit (-11 degrees Celsius) in the evenings. During that month the park also tends to see 2 inches (5 cm) of rainfall on average and an additional 23 inches (58 cm) of snow.
What to pack: Start bundling up as the weather begins to get very cold this season.
Winter in Yellowstone can be long, brutally cold, and incredibly harsh. It can also be a very rewarding time to visit for those who don't mind braving the cold conditions. From December through February, the temperature rarely climbs above 30 degrees Fahrenheit (-1 degree Celsius). Heavy snows can be expected throughout the entire season, with an average of 30, 35, and 25 inches (76, 88, and 63 cm) falling in December, January, and February respectively.
The days also tend to be shorter at this time of the year, with sun rising later and setting earlier. This isn't a case of 24 hours of darkness as in Alaska, but the daylight hours are fleeting and can sometimes catch some travelers off-guard.
What to pack: Bring incredibly warm clothes when visiting during the winter and prepare for a lot of snow.
Winter Travel in Yellowstone
It should be noted that winter travel in Yellowstone is severely limited due to the heavy snowfall and remote nature of the park in general. Most years, the National Park Service begins to close down many of the roads for the season, making it impossible for travelers to arrive at one of the entry points and simply begin exploring the park as they would other times of the year. The one exception to this rule is the road between Mammoth Hot Springs and Yellowstone's northeast entrance, which is open to regular traffic all year long.
By mid-December, the park's roads being to open again, but only to snowmobiles and snowcoaches. These vehicles are especially adept at handling the deep snow and can be used throughout the park. In fact, they are the only means of transportation for reaching places like the Old Faithful Snow Lodge and other points of interest. That means, if you want to travel in Yellowstone during the colder months of the year, you'll need to make arrangements ahead of time for how you'll reach the interior of the park.
The winter roads close once again in mid-March to allow the park's snow plows to begin clearing them of snow. They tend to reopen to the public for regular driving in early-April, although heavy snow remains a possibility into May.
|Average Monthly Temperature, Rainfall, and Daylight Hours|
|Month||Avg. Temp.||Rainfall||Daylight Hours|
|January||24 F||1.7 inches||9 hours|
|February||28 F||1.6 inches||11 hours|
|March||36 F||1.8 inches||12 hours|
|April||43 F||1.8 inches||14 hours|
|May||52 F||2.5 inches||15 hours|
|June||62 F||2.3 inches||16 hours|
|July||72 F||1.6 inches||15 hours|
|August||71 F||1.6 inches||14 hours|
|September||62 F||1.5 inches||13 hours|
|October||48 F||1.2 inches||11 hours|
|November||34 F||1.9 inches||10 hours|
|December||24 F||1.6 inches||9 hours|