Idaho Weather by Month
Idaho, located in the northwestern United States, is known for its diverse landscapes, ranging from rugged mountains and vast forests to high desert plains. This variety in terrain results in a wide range of climates across the state. In general, Idaho experiences four distinct seasons: cold winters, warm summers, and mild springs and falls. The state’s weather patterns are influenced by its elevation and geographic features, with mountainous areas experiencing colder temperatures and significant snowfall during the winter months, while lower-elevation regions, such as the Snake River Plain, have more moderate temperatures and less precipitation. Summers are typically warm and dry, with temperatures often reaching into the 80s°F (27°C) and 90s°F (32°C), especially in the southern part of the state. Idaho’s climate is ideal for a variety of outdoor activities throughout the year, from skiing and snowboarding in the winter to hiking, fishing, and camping in the warmer months. The state’s natural beauty, including iconic landmarks like the Sawtooth Mountains, Shoshone Falls, and Craters of the Moon National Monument, makes it a popular destination for nature lovers and adventure seekers alike.
Average Temperature and Precipitation by Month
| Month | Avg Temp (°F) | Avg Temp (°C) | Avg Precipitation (inches) |
|---|---|---|---|
| January | 23°F | -5°C | 1.5 |
| February | 28°F | -2°C | 1.4 |
| March | 36°F | 2°C | 1.5 |
| April | 45°F | 7°C | 1.4 |
| May | 55°F | 13°C | 1.8 |
| June | 64°F | 18°C | 1.3 |
| July | 72°F | 22°C | 0.5 |
| August | 71°F | 22°C | 0.6 |
| September | 61°F | 16°C | 0.8 |
| October | 48°F | 9°C | 1.1 |
| November | 35°F | 2°C | 1.6 |
| December | 26°F | -3°C | 1.8 |
Monthly Weather, Clothing, and Landmarks
January
Weather: January is the coldest month in Idaho, with temperatures ranging from 10°F to 30°F (-12°C to -1°C) depending on the region. The mountainous areas, including the Sawtooth and Bitterroot ranges, experience heavy snowfall, creating perfect conditions for winter sports. Lower elevations, such as Boise and the Snake River Plain, also experience cold weather, with occasional snow.
Clothing: To stay warm in January, dress in layers with thermal underwear, a heavy winter coat, and insulated gloves and hats. Snow boots are essential for outdoor activities, especially in areas with deep snow. In higher elevations, ski gear is recommended for those planning to hit the slopes.
Landmarks: January is an excellent time to visit Sun Valley, one of Idaho’s premier ski resorts, known for its world-class skiing, snowboarding, and après-ski culture. For those interested in more remote winter adventures, head to the Selkirk Mountains near Sandpoint for snowshoeing, cross-country skiing, and the chance to see wildlife in a serene winter landscape. The Bruneau Dunes State Park in southern Idaho offers a unique experience of exploring sand dunes covered in snow.
February
Weather: February in Idaho remains cold, with temperatures ranging from 15°F to 35°F (-9°C to 2°C). Snowfall continues, particularly in the northern and mountainous regions, providing excellent conditions for winter sports. The southern parts of the state, including Boise, may see a mix of snow and rain, with occasional sunny days breaking through the winter chill.
Clothing: Warm layers, including thermal clothing, a heavy coat, gloves, and hats, are necessary to stay comfortable in February. Snow boots are essential for navigating snowy and icy conditions. In the mountains, proper ski gear is recommended for outdoor activities.
Landmarks: February is a great time to explore the Payette National Forest, where snowmobiling and cross-country skiing are popular activities. The forest’s vast, snowy landscape offers a winter wonderland for adventure seekers. For a more relaxed experience, visit Lava Hot Springs in southeastern Idaho, where you can soak in natural hot springs surrounded by snow-covered landscapes. The winter season also provides a unique opportunity to explore the Craters of the Moon National Monument, where the stark volcanic landscape is transformed by snow, offering a surreal and beautiful sight.
March
Weather: March in Idaho marks the transition from winter to spring, with temperatures ranging from 25°F to 45°F (-4°C to 7°C). Snow is still common, particularly in the northern and higher elevations, but milder days become more frequent, especially in southern Idaho. As the snow begins to melt, rivers and streams start to swell, setting the stage for springtime activities.
Clothing: Layered clothing is ideal for March, as temperatures can fluctuate throughout the day. A medium-weight jacket, along with a hat and gloves, is recommended for colder mornings and evenings. Waterproof boots are useful for navigating slushy or wet conditions.
Landmarks: March is an excellent time to visit Hells Canyon, the deepest river gorge in North America. As the snow melts, the Snake River flows more rapidly, making it a great time for early-season whitewater rafting or jet boat tours. For a more leisurely activity, visit the Idaho Botanical Garden in Boise, where the first signs of spring begin to appear with early-blooming flowers and budding trees. The Sawtooth Mountains also start to open up for late-season snowshoeing or early spring hikes, offering stunning views as winter transitions to spring.
April
Weather: April in Idaho brings a significant change in weather, with temperatures ranging from 35°F to 60°F (2°C to 16°C). The snow continues to melt in the lower elevations, and spring fully takes hold, with blooming wildflowers and greening landscapes. Rain showers become more common, especially in the valleys, while the mountains may still see occasional snowfall.
Clothing: Light layers, including long-sleeved shirts, a medium-weight jacket, and waterproof footwear, are ideal for April. An umbrella or rain jacket is recommended for dealing with spring showers.
Landmarks: April is a wonderful time to visit Shoshone Falls, often referred to as the “Niagara of the West.” The falls are at their most powerful during spring when the snowmelt feeds the Snake River, creating a spectacular display of water cascading over the cliffs. The City of Rocks National Reserve in southern Idaho also begins to thaw, offering excellent opportunities for rock climbing and hiking among the unique granite formations. The Coeur d’Alene Scenic Byway in northern Idaho is a beautiful drive during this time, with views of the lake and blooming wildflowers along the route.
May
Weather: May sees the full arrival of spring in Idaho, with temperatures ranging from 45°F to 70°F (7°C to 21°C). The state experiences mild, pleasant weather, with longer days and abundant sunshine. The snow has largely melted in the valleys, while the higher elevations still retain some snow, making for a striking contrast in the landscape.
Clothing: Light, breathable clothing is ideal for May, including t-shirts, light jackets, and comfortable walking shoes. A rain jacket or umbrella may still be needed for occasional showers.
Landmarks: May is an ideal time to visit the Sawtooth National Recreation Area, where the snowmelt feeds into crystal-clear lakes and rivers, creating perfect conditions for fishing, hiking, and camping. The area’s wildflowers are in full bloom, adding vibrant colors to the stunning mountain scenery. The Snake River Canyon near Twin Falls is another must-visit, where you can enjoy hiking, kayaking, or simply taking in the views from the Perrine Bridge. Additionally, Boise’s Greenbelt, a 25-mile pathway along the Boise River, is perfect for walking, cycling, and enjoying the fresh spring air.
June
Weather: June ushers in summer across Idaho, with temperatures ranging from 55°F to 80°F (13°C to 27°C). The weather is warm, with increasing daylight hours and minimal rainfall. The state’s landscapes are lush and green, and the rivers are full from the snowmelt, making it an ideal time for outdoor activities.
Clothing: Light, breathable clothing such as shorts, t-shirts, and sandals is recommended for June. A hat, sunglasses, and sunscreen are essential for sun protection, and a light jacket may be useful for cooler evenings, especially in higher elevations.
Landmarks: June is an excellent time to explore the Frank Church-River of No Return Wilderness, one of the largest wilderness areas in the lower 48 states. The wilderness offers unparalleled opportunities for rafting, kayaking, and backpacking in a remote and pristine environment. For a more accessible adventure, visit Craters of the Moon National Monument, where you can hike through lava fields, cinder cones, and caves. The warm weather also makes it a great time to visit the Sun Valley area for mountain biking, horseback riding, and scenic chairlift rides.
July
Weather: July is the warmest month in Idaho, with temperatures ranging from 60°F to 90°F (16°C to 32°C). The weather is hot and dry, especially in southern Idaho, with long days and minimal rainfall. This is peak season for outdoor activities, with ideal conditions for hiking, camping, and water sports.
Clothing: Wear light, breathable clothing such as shorts, tank tops, and sandals. Sun protection is crucial, so be sure to use sunscreen, wear sunglasses, and a hat. A light jacket might be useful for cooler evenings, especially in the mountains.
Landmarks: July is perfect for exploring the lakes of northern Idaho, such as Lake Coeur d’Alene and Priest Lake, where you can enjoy boating, fishing, and swimming. The McCall area, located on Payette Lake, is a popular summer destination offering a variety of water activities, hiking, and mountain biking. For a unique experience, visit the St. Anthony Sand Dunes in eastern Idaho, where you can ride ATVs, camp under the stars, and explore the vast dunes that rise up to 400 feet high.
August
Weather: August continues the warm and dry trend in Idaho, with temperatures ranging from 58°F to 88°F (14°C to 31°C). The heat is still intense, particularly in the southern parts of the state, but the evenings begin to cool slightly. This is an excellent time for late-summer outdoor activities and exploring Idaho’s natural beauty.
Clothing: Light, airy clothing is recommended in August, including shorts, t-shirts, and sandals. Sun protection remains important, so use sunscreen, wear sunglasses, and a hat. A light jacket might be needed for cooler evenings, particularly in higher elevations.
Landmarks: August is a great time to visit the Idaho Panhandle National Forests, where you can hike through lush forests, fish in clear mountain streams, and explore scenic byways like the Lake Pend Oreille Scenic Byway. The Sawtooth Mountains are also stunning in August, offering endless opportunities for backpacking, rock climbing, and stargazing in the clear, dark skies. For a cultural experience, attend the Western Idaho Fair in Boise, where you can enjoy live music, rodeos, and traditional fair attractions.
September
Weather: September in Idaho brings the first hints of fall, with temperatures ranging from 50°F to 75°F (10°C to 24°C). The weather remains warm, but the heat begins to ease, and the nights become cooler. This is a perfect time for outdoor activities as the summer crowds thin out, and the state’s landscapes start to show the first signs of autumn.
Clothing: Light layers are ideal for September, with t-shirts and shorts for the warmer parts of the day and a light jacket or sweater for cooler mornings and evenings. Comfortable walking shoes are recommended for exploring outdoor areas.
Landmarks: September is an ideal time to visit the Owyhee Canyonlands in southwestern Idaho, known for its rugged beauty and remote wilderness. The cooler temperatures make it perfect for hiking, rock climbing, and exploring the deep canyons and unique rock formations. The Stanley Basin, surrounded by the Sawtooth Mountains, is another must-visit, offering excellent opportunities for fishing, kayaking, and hiking among the fall foliage. The Sun Valley Jazz Festival in late September is a great cultural event, attracting music lovers from around the world.
October
Weather: October sees a significant drop in temperatures across Idaho, ranging from 40°F to 65°F (4°C to 18°C). The fall foliage reaches its peak, especially in the northern and central parts of the state. The weather is typically dry and sunny, making it one of the most beautiful times to explore Idaho’s outdoors.
Clothing: Warmer layers, including sweaters, jackets, and long pants, are necessary for October. A heavier coat may be needed for cold days, especially in the mountains. Comfortable walking shoes are essential for exploring trails and parks.
Landmarks: October is a perfect time to visit the Salmon River, also known as the “River of No Return,” for a rafting or fishing adventure amid stunning fall colors. The Teton Valley in eastern Idaho is also breathtaking during this time, with vibrant autumn foliage and clear views of the Tetons. For a unique experience, visit the Old Idaho Penitentiary in Boise, which hosts special Halloween events and tours during the month of October, offering a glimpse into Idaho’s history with a spooky twist.
November
Weather: November in Idaho sees the onset of winter, with temperatures dropping to between 30°F and 50°F (-1°C to 10°C). Snowfall becomes more frequent, particularly in the northern and mountainous regions, signaling the start of the winter sports season. The valleys experience colder temperatures, with occasional snow and more frequent overcast days.
Clothing: Warm layers, including sweaters, jackets, and long pants, are necessary for November. A winter coat, gloves, and a hat may be needed for colder days, particularly in the mountains. Waterproof boots are recommended for dealing with wet or snowy conditions.
Landmarks: November marks the beginning of the ski season in Idaho, with resorts like Sun Valley, Schweitzer Mountain, and Brundage Mountain opening their slopes. For a cultural experience, visit the Idaho State Capitol in Boise, where you can learn about the state’s history and government while staying warm indoors. The Boise Art Museum is another great destination, offering a mix of contemporary and traditional art exhibitions.
December
Weather: December in Idaho is characterized by cold temperatures and frequent snowfall, especially in the mountains. Average temperatures range from 20°F to 40°F (-6°C to 4°C). The state’s landscape is often blanketed in snow, creating a winter wonderland perfect for skiing, snowboarding, and other winter sports.
Clothing: Heavy winter clothing, including down jackets, thermal layers, gloves, and scarves, is necessary for staying warm in December. Waterproof boots and snow gear are essential for those visiting the mountains or participating in winter sports.
Landmarks: December is the perfect time to enjoy Idaho’s winter activities. Visit Sun Valley Resort for world-class skiing, snowboarding, and festive holiday events. The McCall Winter Carnival, although starting in late January, is worth planning for, offering snow sculptures, parades, and winter sports in a charming mountain town setting. For a quieter experience, head to the Sawtooth National Recreation Area, where you can enjoy snowshoeing or cross-country skiing in a serene, snow-covered landscape.
