Last updated: January 18, 2025
Idaho's climate is characterized by a diverse array of Köppen-Geiger climate classes, including Dsc, Csb, Cfb, Csa, Dsb, Dfb, and BSk. This variety reflects the state's unique geography, leading to significant temperature fluctuations across the year. Winter temperatures can plummet to a staggering -33°C (-28°F) in December, while summer sees a blistering peak of 44°C (111°F) in August. The state's average temperature hovers around 9°C (49°F), illustrating its transition from harsh winters to warm summers. Overall, Idaho offers a fascinating climatological tapestry that shapes its ecosystems and influences the lifestyle of its residents.
Idaho experiences notable seasonal temperature patterns that reflect its continental climate. Winter months, particularly January and February, witness extreme cold, with minimum temperatures dropping as low as -33°C (-27°F) and -29°C (-20°F), respectively, while daily averages remain below freezing. As spring approaches, temperatures gradually rise, with March and April seeing more moderate conditions, including a significant shift to milder averages around 3°C (39°F) in March and a maximum of 33°C (92°F) in April. The arrival of summer ushers in warmth, peaking in August with maximum temperatures reaching 44°C (111°F), while average temperatures hover around 22°C (72°F). As the year progresses into fall, temperatures start to decline, with September still relatively warm before October and November bring notable drops, as minimums plunge back down towards winter extremes. This dynamic climate creates stark contrasts, shaping both the natural landscape and the daily lives of Idaho’s residents.
Twin Falls, Coeur d'Alene, and Sun Valley in Idaho each exhibit distinct temperature ranges throughout the year. In Twin Falls, temperatures reach a frigid minimum of -27°C (-16°F) in January and soar to a scorching 41°C (106°F) in August. For more details on the monthly temperature in Twin Falls. Coeur d'Alene experiences slightly different extremes, with temperatures dipping to -23°C (-9°F) in February and climbing to a record high of 42°C (109°F) in June; you can explore the monthly temperature in Coeur d'Alene. Meanwhile, Sun Valley's climate is characterized by a minimum temperature of -27°C (-16°F) in January and a maximum of 30°C (86°F) in August, with further information available on the monthly temperature in Sun Valley.
Idaho's precipitation patterns are marked by significant variation throughout the year, with the winter months receiving the highest amounts. January and February lead with 63 mm (2.5 in) and 78 mm (3.1 in) of precipitation, accompanied by around 10 to 13 rainy days, setting a wet tone for the season. As spring arrives, March and April maintain moderate levels of precipitation at 58 mm (2.3 in) and 59 mm (2.3 in), while May brings a slight reduction to 55 mm (2.2 in), with each month averaging close to 9 to 11 days of rain.
The summer months exhibit a stark decrease in precipitation, with July and August receiving only 8 mm (0.3 in) and 16 mm (0.6 in), respectively, signaling dry conditions with merely 1 to 2 rainy days. September marks a gradual return to wetter conditions with 29 mm (1.1 in) over 4 days, while October and November bring back the rain with totals of 50 mm (2.0 in) and 60 mm (2.4 in) over 7 to 10 days. December sees precipitation levels similar to January, ensuring that the cycle of moisture continues as the region transitions into winter.
Idaho experiences a clear seasonal trend in sunshine duration that reflects the region's distinct climatic changes throughout the year. The year begins with relatively low sunshine hours, with January receiving just 120 hours of sunlight. However, as winter transitions into spring, sunshine hours gradually increase; by March, they reach 247 hours, culminating in an impressive 280 hours in April. This upward trajectory continues into late spring and early summer, with May basking in 336 hours of sun, and June marking the beginning of the peak sunshine period at 367 hours. July radiates the most sunlight, boasting 401 hours, making it the sunniest month in Idaho.
As summer fades into fall, sunshine hours begin to decline, but September still enjoys a respectable 298 hours of sunlight. By October, this number drops further to 247 hours, as the days grow shorter and the crisp autumn air sets in. The transition to winter brings back reduced sunlight again, with November providing just 182 hours and December concluding the year with a mere 147 hours. This pattern highlights Idaho’s marked seasonal variability, underscoring the summer months as optimal for outdoor activities, while the colder months are characterized by significantly less sunlight, shaping both the natural environment and the lifestyle of its residents.
Idaho's UV Index (UVI) exhibits a pronounced seasonal pattern, reflecting the intensity of solar radiation throughout the year. Starting off the year, January and December see relatively low UV levels at UVI 3, indicating moderate exposure risks. As winter transitions into spring, UV radiation increases, peaking in March with a UVI of 8. April continues this upward trend, reaching 10, while May marks a significant escalation as the UVI reaches 11, signaling that outdoor sun safety becomes increasingly crucial.
The summer months, particularly June, represent the pinnacle of solar exposure, with a UVI peak of 12 in June, indicating heightened risk for harm from unprotected sun exposure. Following June, July and August maintain high levels of UV radiation at 11. As fall approaches, the UVI gradually declines, with September reflecting a decrease to 9, and October dropping further to 6. By November, the UVI stabilizes at 5, before returning to winter levels of 3 in December. This cyclical variation highlights the importance of sun protection during the warmer months, particularly from late spring through summer when UV exposure poses the greatest risks.
UV Risk Categories
Idaho experiences distinct variations in daylight duration throughout the year, reflecting the changes associated with seasons. January begins the year with only 9 hours of daylight, gradually increasing to 10 hours in February and 11 hours in March as winter transitions into spring. April introduces longer days, reaching 13 hours, while May continues the trend, offering 14 hours of daylight. This increase peaks in June, with 15 hours of sunlight, creating perfect conditions for outdoor activities and exploration during the summer months.
As summer wanes, daylight hours begin to taper off, with July still providing 15 hours but giving way to shorter days in August at 13 hours. September witnesses a further reduction to 12 hours as autumn sets in. The decline continues through October, when daylight dips to 10 hours, and November sees a return to 9 hours. By December, the shortest day of the year occurs, with only 8 hours of daylight. This rhythmic fluctuation in daylight duration highlights Idaho’s seasonal cycles and influences both the recreational opportunities and lifestyles of its residents.
Coeur d'Alene, Idaho, experiences a diverse climate with cold winters and warm summers. Winter temperatures can drop as low as -23°C (-9°F) in February, while summer highs often reach 42°C (109°F) in June and July. Precipitation is highest during the winter months, peaking at 115 mm (4.5 in) in November, while July is notably dry with just 6 mm (0.3 in). The region enjoys increased sunshine from March through August, with July having the most at 411 hours. For more detailed information, you can visit the Coeur d'Alene climate.
Hayden Lake, United States, experiences a varied climate with cold winters and warm summers. Winter months, such as January and February, see temperatures dipping to as low as -23°C (-9°F) and average precipitation around 100 mm (4.0 in). The summer months of June, July, and August are warmer, with average temperatures reaching up to 22°C (71°F), minimal rainfall, and lengthy sunshine durations topping 411 hours in July. Autumn and spring are transitional, featuring moderate temperatures and increased rainfall and sunshine compared to winter. For more detailed climate information, visit the Hayden Lake climate.
Horseshoe Bend, United States, experiences significant seasonal variations in temperature and precipitation. Winters can be harsh, with January seeing temperatures ranging from -24°C (-11°F) to 11°C (52°F) and receiving about 77 mm (3.0 in) of precipitation. In contrast, summers are warm and dry, highlighted by July's temperatures from 6°C (44°F) to 38°C (100°F) and a meager 3 mm (0.1 in) of rainfall. Annual sunshine gradually peaks in July with 402 hours, offering long days and abundant sunshine, before decreasing towards the end of the year. For more detailed information, visit Horseshoe Bend climate.
McCall, Idaho, experiences a diverse climate, characterized by cold winters and warm summers. January and February are the coldest months, with temperatures ranging from a low of -22°C (-7°F) to a high of 6°C (43°F), while summer temperatures in July and August can reach up to 34°C (93°F). The region receives substantial precipitation, with February being the wettest month at 160 mm (6.3 in), while July sees only 13 mm (0.5 in). Sunshine is plentiful in the summer, peaking in July with 403 hours, contrasting with January's 112 hours. For more detailed climate data, see the McCall climate.
Sandpoint, located in the United States, experiences a diverse climate characterized by cold winters and warm summers. In the winter months, temperatures range from -18°C (0°F) to 13°C (56°F) with substantial precipitation, peaking at 145 mm (5.7 in) in December. Summer months bring warmer temperatures, with highs reaching up to 41°C (106°F) in June and comparatively less rainfall, notably only 8 mm (0.3 in) in July. February and November see significant rainfalls exceeding 100 mm (4 in), while sunshine reaches a maximum of 412 hours in July, providing ample daylight. For more detailed information, visit Sandpoint climate.
Sun Valley, located in the United States, experiences cold winters with January temperatures ranging from -27°C (-16°F) to 2°C (36°F), while July offers a relatively mild climate with temperatures reaching up to 28°C (83°F). The region receives varied precipitation throughout the year, averaging as much as 86 mm (3.4 in) in February but dropping to just 15 mm (0.6 in) in July. Sunshine duration is considerable, peaking at 402 hours in July, and providing plenty of sunlight from spring through fall. For more information, you can visit the Sun Valley climate page.
Twin Falls, Idaho, experiences a varied climate with distinct seasonal changes. Winters are cold, with average temperatures in January around -1°C (31°F) and lows that can plunge to -27°C (-16°F), complemented by moderate precipitation of about 40 mm (1.6 in) throughout the month. Summers are notably warm, with July reaching an average of 26°C (80°F) and highs up to 40°C (104°F), while receiving minimal rainfall, roughly 5 mm (0.2 in). The region enjoys abundant sunshine year-round, peaking at 391 hours in July, making it ideal for outdoor activities during the summer months. For more details, visit the Twin Falls climate.
In conclusion, Idaho's climate and environmental patterns showcase remarkable seasonal variations that profoundly impact its geography, ecosystems, and the lifestyle of its inhabitants. From the diverse precipitation and temperature ranges to the varying sunshine hours and UV Index, these elements create a unique tapestry of climate conditions throughout the year. Understanding these seasonal trends not only highlights the beauty and challenges of life in Idaho but also underscores the importance of adapting to these changes, whether through outdoor recreation, agriculture, or community planning. As residents and visitors engage with Idaho's natural landscape, awareness of its climatic nuances will enhance their experiences and promote a deeper appreciation for this stunning region.