Idaho has a temperate climate with warm summers and cold winters.
Idaho has an average annual temperature of 48.2°F across all 10 cities, with approximately 487 mm of annual precipitation and average humidity of 61%. Temperatures peak in July and drop to their lowest in January, while rainfall is highest during winter months.
The warmest city is Caldwell with average July highs of 93.0°F, while Rexburg is the coldest with average January lows of 8.1°F. Humidity remains moderate throughout the year, especially during winter months, creating cold and dry conditions. These seasonal patterns make summer pleasant for travel, while winters can bring frost and occasional snowfall.
| Month | 🌤️ | Avg High | Avg Temp | Avg Low | Record High | Record Low | Humid % | Rain (mm) | Wind (m/s) | Solar (kWh/m²) |
|---|---|---|---|---|---|---|---|---|---|---|
| January | ❄️ | 33.6°F | 26.1°F | 18.5°F | 64.0°F | -28.1°F | 86% | 55 | 2.0 | 1.60 |
| February | ❄️ | 38.7°F | 30.2°F | 21.6°F | 69.6°F | -31.4°F | 79% | 45 | 2.2 | 2.60 |
| March | 🌤️ | 48.4°F | 38.5°F | 28.4°F | 79.2°F | -18.2°F | 70% | 50 | 2.3 | 3.90 |
| April | 🌤️ | 56.8°F | 45.3°F | 33.6°F | 90.3°F | 6.8°F | 62% | 42 | 2.3 | 5.30 |
| May | 🌤️ | 66.9°F | 54.5°F | 42.1°F | 101.1°F | 20.7°F | 57% | 49 | 2.2 | 6.40 |
| June | ☀️ | 76.8°F | 63.5°F | 50.2°F | 110.8°F | 27.3°F | 50% | 34 | 2.1 | 7.20 |
| July | 😎 | 87.8°F | 73.2°F | 58.8°F | 110.8°F | 36.3°F | 39% | 16 | 2.0 | 7.50 |
| August | 😎 | 86.5°F | 72.3°F | 57.9°F | 108.9°F | 33.3°F | 37% | 17 | 1.9 | 6.40 |
| September | ☀️ | 75.9°F | 62.6°F | 49.1°F | 106.7°F | 19.6°F | 42% | 24 | 1.9 | 5.00 |
| October | 🌤️ | 60.6°F | 49.3°F | 37.8°F | 95.0°F | -2.2°F | 55% | 36 | 2.0 | 3.30 |
| November | 🌤️ | 44.4°F | 36.0°F | 27.5°F | 76.8°F | -18.0°F | 72% | 55 | 2.1 | 1.90 |
| December | ❄️ | 33.8°F | 26.4°F | 19.2°F | 63.0°F | -34.4°F | 83% | 63 | 2.1 | 1.30 |
Showing average climate conditions across 45 years (1981–2025) · averaged across all 10 cities in Idaho
🧥 Expect frosty nights and below-freezing temperatures during this Cold Winter period.
🌤️ Early mornings and evenings are most comfortable during this Hot Summer season.
☔ Rainfall is spread across the year with no sharply defined wet season.
Region-wide monthly averages across 10 cities · 1981–2025 · °F
Temperatures rise steadily from spring, peak in July, and gradually decline through autumn into winter.
These seasonal patterns make summer pleasant for travel, while winters can bring frost and occasional snowfall.
Region-wide monthly rainfall · 1981–2025 · mm/month
💧 Humidity peaks at 86% in January · annual avg 61%
Monthly averages · 1981–2025
Across 45 years, Idaho's temperature has remained relatively stable over the past decade. 2025 was the warmest year overall and 1985 the coolest.
The warmest year on record was 2025 (avg: 51.1°F), while the coldest year was 1985 (avg: 44.2°F).
Averaged across all 10 cities in Idaho · Last 30 years · °F
Averaged across all 10 cities in Idaho · Last 30 years · mm/year
🔥 hottest · ❄️ coldest · 🌧️ wettest
ℹ️ Values are averages across all 10 cities in Idaho for each year.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall (mm) | Avg Humidity | Avg Wind |
|---|---|---|---|---|---|---|---|---|
2025 🔥 | 62.2°F | 51.1°F | 39.9°F | 104.0°F | -26.0°F | 517 | 60% | 2.1 m/s |
2024 | 61.2°F | 50.2°F | 39.4°F | 108.5°F | -27.0°F | 544 | 61% | 2.1 m/s |
2023 | 59.2°F | 48.7°F | 38.3°F | 105.4°F | -27.9°F | 528 | 64% | 2.0 m/s |
2022 | 59.2°F | 48.2°F | 37.0°F | 106.7°F | -30.8°F | 491 | 61% | 2.0 m/s |
2021 | 61.7°F | 50.4°F | 39.0°F | 107.2°F | -5.6°F | 452 | 57% | 2.1 m/s |
2020 | 60.1°F | 49.1°F | 37.9°F | 105.6°F | -11.2°F | 508 | 59% | 2.2 m/s |
2019 | 58.1°F | 47.7°F | 37.0°F | 103.3°F | -14.8°F | 467 | 63% | 2.1 m/s |
2018 | 59.5°F | 48.7°F | 37.9°F | 108.9°F | -13.5°F | 473 | 61% | 2.1 m/s |
2017 | 58.5°F | 48.0°F | 37.4°F | 105.3°F | -26.9°F | 639 | 65% | 2.0 m/s |
2016 | 60.4°F | 49.5°F | 38.3°F | 103.3°F | -27.2°F | 547 | 62% | 2.1 m/s |
Showing 1 to 10 of 45 years
All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.
