Climate and Average Weather Year Round in Eagle Idaho, United States

In Eagle, the summers are short, hot, dry, and mostly clear and the winters are very cold, snowy, and partly cloudy. Over the course of the year, the temperature typically varies from 23°F to 92°F and is rarely below 9°F or above 100°F.

Based on the tourism score, the best time of year to visit Eagle for warm-weather activities is from late June to late August.

The hot season lasts for 2.9 months, from June 14 to September 12, with an average daily high temperature above 81°F. The hottest month of the year in Eagle is July, with an average high of 91°F and low of 60°F.

The cold season lasts for 3.0 months, from November 19 to February 19, with an average daily high temperature below 47°F. The coldest month of the year in Eagle is December, with an average low of 25°F and high of 37°F.

In Eagle, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.

The clearer part of the year in Eagle begins around June 10 and lasts for 4.1 months, ending around October 13.

The clearest month of the year in Eagle is August, during which on average the sky is clear, mostly clear, or partly cloudy 81% of the time.

The cloudier part of the year begins around October 13 and lasts for 7.9 months, ending around June 10.

The cloudiest month of the year in Eagle is January, during which on average the sky is overcast or mostly cloudy 58% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Eagle varies throughout the year.

The wetter season lasts 7.3 months, from October 23 to June 3, with a greater than 15% chance of a given day being a wet day. The month with the most wet days in Eagle is December, with an average of 8.0 days with at least 0.04 inches of precipitation.

The drier season lasts 4.6 months, from June 3 to October 23. The month with the fewest wet days in Eagle is July, with an average of 1.4 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in Eagle is November, with an average of 6.5 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 23% on November 19.

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Eagle experiences some seasonal variation in monthly rainfall.

The rainy period of the year lasts for 9.1 months, from September 18 to June 21, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain in Eagle is December, with an average rainfall of 1.5 inches.

The rainless period of the year lasts for 2.9 months, from June 21 to September 18. The month with the least rain in Eagle is July, with an average rainfall of 0.2 inches.

Snowfall

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Eagle experiences some seasonal variation in monthly snowfall.

The snowy period of the year lasts for 3.1 months, from November 15 to February 17, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow in Eagle is December, with an average snowfall of 3.2 inches.

The snowless period of the year lasts for 8.9 months, from February 17 to November 15. The least snow falls around July 11, with an average total accumulation of 0.0 inches.

The length of the day in Eagle varies significantly over the course of the year. In 2023, the shortest day is December 21, with 8 hours, 55 minutes of daylight; the longest day is June 21, with 15 hours, 27 minutes of daylight.

The earliest sunrise is at 6:03 AM on June 15, and the latest sunrise is 2 hours, 22 minutes later at 8:25 AM on November 4. The earliest sunset is at 5:08 PM on December 9, and the latest sunset is 4 hours, 23 minutes later at 9:31 PM on June 27.

Daylight saving time (DST) is observed in Eagle during 2023, starting in the spring on March 12, lasting 7.8 months, and ending in the fall on November 5.

The figure below presents a compact representation of key lunar data for 2023. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The perceived humidity level in Eagle, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Eagle experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 4.4 months, from February 9 to June 21, with average wind speeds of more than 6.7 miles per hour. The windiest month of the year in Eagle is April, with an average hourly wind speed of 7.2 miles per hour.

The calmer time of year lasts for 7.6 months, from June 21 to February 9. The calmest month of the year in Eagle is September, with an average hourly wind speed of 6.1 miles per hour.

The predominant average hourly wind direction in Eagle varies throughout the year.

The wind is most often from the west for 7.7 months, from March 13 to November 3, with a peak percentage of 42% on June 21. The wind is most often from the south for 3.0 weeks, from November 3 to November 24, with a peak percentage of 30% on November 22. The wind is most often from the east for 3.6 months, from November 24 to March 13, with a peak percentage of 35% on January 1.

To characterize how pleasant the weather is in Eagle throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Eagle for general outdoor tourist activities is from late June to late August, with a peak score in the last week of July.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Eagle for hot-weather activities is from mid July to mid August, with a peak score in the last week of July.

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

The growing season in Eagle typically lasts for 5.9 months (179 days), from around April 23 to around October 19, rarely starting before March 31 or after May 13, and rarely ending before September 28 or after November 9.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

Based on growing degree days alone, the first spring blooms in Eagle should appear around April 9, only rarely appearing before March 27 or after April 28.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.

The brighter period of the year lasts for 3.2 months, from May 14 to August 21, with an average daily incident shortwave energy per square meter above 6.8 kWh. The brightest month of the year in Eagle is July, with an average of 8.0 kWh.

The darker period of the year lasts for 3.6 months, from October 30 to February 16, with an average daily incident shortwave energy per square meter below 2.9 kWh. The darkest month of the year in Eagle is December, with an average of 1.6 kWh.

For the purposes of this report, the geographical coordinates of Eagle are 43.695 deg latitude, -116.354 deg longitude, and 2,562 ft elevation.

The topography within 2 miles of Eagle contains only modest variations in elevation, with a maximum elevation change of 151 feet and an average elevation above sea level of 2,578 feet. Within 10 miles contains only modest variations in elevation (3,186 feet). Within 50 miles contains large variations in elevation (7,316 feet).

The area within 2 miles of Eagle is covered by cropland (49%) and artificial surfaces (48%), within 10 miles by grassland (40%) and cropland (29%), and within 50 miles by shrubs (45%) and grassland (25%).