Average Weather in American Falls Idaho, United States
In American Falls, the summers are hot and mostly clear, the winters are freezing and partly cloudy, and it is dry year round. Over the course of the year, the temperature typically varies from 18°F to 89°F and is rarely below 1°F or above 96°F.
Based on the tourism score, the best time of year to visit American Falls for warm-weather activities is from late June to late August.
The hot season lasts for 3.0 months, from June 13 to September 14, with an average daily high temperature above 78°F. The hottest day of the year is July 31, with an average high of 89°F and low of 56°F.
The cold season lasts for 3.2 months, from November 20 to February 26, with an average daily high temperature below 43°F. The coldest day of the year is December 30, with an average low of 18°F and high of 32°F.
Average High and Low Temperature
Average Hourly Temperature
In American Falls, 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 American Falls begins around June 8 and lasts for 4.3 months, ending around October 16. On July 26, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 82% of the time, and overcast or mostly cloudy 18% of the time.
The cloudier part of the year begins around October 16 and lasts for 7.7 months, ending around June 8. On January 17, the cloudiest day of the year, the sky is overcast or mostly cloudy 57% of the time, and clear, mostly clear, or partly cloudy 43% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in American Falls varies throughout the year.
The wetter season lasts 8.0 months, from October 14 to June 14, with a greater than 13% chance of a given day being a wet day. The chance of a wet day peaks at 20% on May 23.
The drier season lasts 4.0 months, from June 14 to October 14. The smallest chance of a wet day is 5% on July 5.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 20% on May 23.
Daily Chance of Precipitation
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. American Falls experiences some seasonal variation in monthly rainfall.
The rainy period of the year lasts for 9.8 months, from August 28 to June 22, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around May 16, with an average total accumulation of 1.2 inches.
The rainless period of the year lasts for 2.2 months, from June 22 to August 28. The least rain falls around July 8, with an average total accumulation of 0.3 inches.
Average Monthly Rainfall
We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. American Falls experiences some seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 3.8 months, from November 10 to March 2, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around December 19, with an average total liquid-equivalent accumulation of 0.3 inches.
The snowless period of the year lasts for 8.2 months, from March 2 to November 10. The least snow falls around July 20, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in American Falls varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 2 minutes of daylight; the longest day is June 21, with 15 hours, 20 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:52 AM on June 14, and the latest sunrise is 2 hours, 16 minutes later at 8:08 AM on November 3. The earliest sunset is at 4:57 PM on December 8, and the latest sunset is 4 hours, 17 minutes later at 9:13 PM on June 26.
Daylight saving time (DST) is observed in American Falls during 2018, starting in the spring on March 11, lasting 7.8 months, and ending in the fall on November 4.
Sunrise & Sunset with Twilight and Daylight Saving Time
The perceived humidity level in American Falls, 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.
Humidity Comfort Levels
The average hourly wind speed in American Falls experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 3.4 months, from February 7 to May 18, with average wind speeds of more than 8.2 miles per hour. The windiest day of the year is March 29, with an average hourly wind speed of 9.4 miles per hour.
The calmer time of year lasts for 8.6 months, from May 18 to February 7. The calmest day of the year is August 4, with an average hourly wind speed of 7.0 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in American Falls varies throughout the year.
The wind is most often from the west for 8.9 months, from February 6 to November 4, with a peak percentage of 53% on June 21. The wind is most often from the south for 3.1 months, from November 4 to February 6, with a peak percentage of 40% on January 1.
Best Time of Year to Visit
To characterize how pleasant the weather is in American Falls 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 American Falls 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 American Falls for hot-weather activities is from early July to mid August, with a peak score in the last week of July.
The growing season in American Falls typically lasts for 4.6 months (142 days), from around May 9 to around September 28, rarely starting before April 21 or after May 28, and rarely ending before September 9 or after October 20.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms in American Falls should appear around April 22, only rarely appearing before April 8 or after May 10.
Growing Degree Days
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 3.1 months, from May 16 to August 19, with an average daily incident shortwave energy per square meter above 7.0 kWh. The brightest day of the year is June 29, with an average of 8.3 kWh.
The darker period of the year lasts for 3.5 months, from October 31 to February 14, with an average daily incident shortwave energy per square meter below 3.1 kWh. The darkest day of the year is December 21, with an average of 1.8 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of American Falls are 42.786 deg latitude, -112.854 deg longitude, and 4,400 ft elevation.
The topography within 2 miles of American Falls contains only modest variations in elevation, with a maximum elevation change of 466 feet and an average elevation above sea level of 4,427 feet. Within 10 miles contains only modest variations in elevation (2,644 feet). Within 50 miles contains large variations in elevation (5,207 feet).
The area within 2 miles of American Falls is covered by water (37%), cropland (29%), shrubs (15%), and artificial surfaces (11%), within 10 miles by cropland (54%) and shrubs (28%), and within 50 miles by shrubs (56%) and cropland (23%).
This report illustrates the typical weather in American Falls, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in American Falls.
For each station, the records are corrected for the elevation difference between that station and American Falls according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at American Falls is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between American Falls and a given station.
The stations contributing to this reconstruction are: Pocatello Regional Airport (72%, 28 kilometers, northeast); Burley Municipal Airport (15%, 79 kilometers, west); and Malad City Airport (14%, 83 kilometers, southeast).
Time zones for aiports and weather stations are provided by AskGeo.com .