Average Weather at Nampa Municipal Airport Idaho, United States
At Nampa Municipal Airport, the summers are short, hot, dry, and mostly clear and the winters are very cold and partly cloudy. Over the course of the year, the temperature typically varies from 23°F to 92°F and is rarely below 8°F or above 100°F.
Based on the tourism score, the best time of year to visit Nampa Municipal Airport for warm-weather activities is from late June to late August.
The hot season lasts for 2.9 months, from June 14 to September 11, with an average daily high temperature above 81°F. The hottest day of the year is July 26, with an average high of 92°F and low of 60°F.
The cold season lasts for 3.0 months, from November 19 to February 18, with an average daily high temperature below 47°F. The coldest day of the year is January 1, with an average low of 23°F and high of 35°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
At Nampa Municipal Airport, 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 at Nampa Municipal Airport begins around June 9 and lasts for 4.1 months, ending around October 12. On July 28, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 84% of the time, and overcast or mostly cloudy 16% of the time.
The cloudier part of the year begins around October 12 and lasts for 7.9 months, ending around June 9. On January 11, the cloudiest day of the year, the sky is overcast or mostly cloudy 59% of the time, and clear, mostly clear, or partly cloudy 41% of the time.
Cloud Cover Categories
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at Nampa Municipal Airport varies throughout the year.
The wetter season lasts 7.3 months, from October 23 to June 2, with a greater than 14% chance of a given day being a wet day. The chance of a wet day peaks at 25% on December 1.
The drier season lasts 4.7 months, from June 2 to October 23. The smallest chance of a wet day is 3% on July 28.
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 21% on March 16.
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. Nampa Municipal Airport experiences some seasonal variation in monthly rainfall.
The rainy period of the year lasts for 8.8 months, from September 25 to June 18, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around December 6, with an average total accumulation of 1.2 inches.
The rainless period of the year lasts for 3.2 months, from June 18 to September 25. The least rain falls around August 1, with an average total accumulation of 0.2 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. Nampa Municipal Airport experiences some seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 3.0 months, from November 14 to February 16, 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 27, with an average total liquid-equivalent accumulation of 0.4 inches.
The snowless period of the year lasts for 9.0 months, from February 16 to November 14. The least snow falls around July 10, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
The length of the day at Nampa Municipal Airport varies significantly over the course of the year. In 2018, the shortest day is December 21, with 8 hours, 56 minutes of daylight; the longest day is June 21, with 15 hours, 26 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 6:04 AM on June 15, and the latest sunrise is 2 hours, 20 minutes later at 8:24 AM on November 3. The earliest sunset is at 5:09 PM on December 9, and the latest sunset is 4 hours, 22 minutes later at 9:31 PM on June 26.
Daylight saving time (DST) is observed at Nampa Municipal Airport 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 at Nampa Municipal Airport, 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
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed at Nampa Municipal Airport experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 4.6 months, from February 5 to June 24, with average wind speeds of more than 6.8 miles per hour. The windiest day of the year is March 31, with an average hourly wind speed of 7.6 miles per hour.
The calmer time of year lasts for 7.3 months, from June 24 to February 5. The calmest day of the year is September 15, with an average hourly wind speed of 6.0 miles per hour.
Average Wind Speed
The predominant average hourly wind direction at Nampa Municipal Airport varies throughout the year.
The wind is most often from the west for 7.8 months, from March 6 to October 31, with a peak percentage of 44% on July 12. The wind is most often from the south for 4.2 months, from October 31 to March 6, with a peak percentage of 36% on January 1.
Best Time of Year to Visit
To characterize how pleasant the weather is at Nampa Municipal Airport 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 Nampa Municipal Airport 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 Nampa Municipal Airport for hot-weather activities is from mid July to mid August, with a peak score in the last week of July.
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.
The growing season at Nampa Municipal Airport typically lasts for 5.6 months (170 days), from around April 26 to around October 13, rarely starting before April 3 or after May 17, and rarely ending before September 23 or after November 6.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms at Nampa Municipal Airport should appear around April 9, only rarely appearing before March 27 or after April 28.
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 3.3 months, from May 13 to August 21, with an average daily incident shortwave energy per square meter above 6.8 kWh. The brightest day of the year is July 3, with an average of 8.1 kWh.
The darker period of the year lasts for 3.6 months, from October 30 to February 15, with an average daily incident shortwave energy per square meter below 2.9 kWh. The darkest day of the year is December 22, with an average of 1.6 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Nampa Municipal Airport are 43.581 deg latitude, -116.523 deg longitude, and 2,516 ft elevation.
The topography within 2 miles of Nampa Municipal Airport contains only modest variations in elevation, with a maximum elevation change of 171 feet and an average elevation above sea level of 2,536 feet. Within 10 miles contains only modest variations in elevation (801 feet). Within 50 miles contains significant variations in elevation (6,496 feet).
The area within 2 miles of Nampa Municipal Airport is covered by cropland (46%), artificial surfaces (38%), and shrubs (14%), within 10 miles by cropland (72%) and artificial surfaces (17%), and within 50 miles by shrubs (49%) and grassland (25%).
This report illustrates the typical weather at Nampa Municipal Airport, 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
Nampa Municipal Airport has a weather station that reported reliably enough during the analysis period that we have included it in our network. When available, historical temperature and dew point measurements are taken directly from this weather station. These records are obtained from NOAA's Integrated Surface Hourly data set, falling back on ICAO METAR records as required.
In the case of missing or erroneous measurements from this station, we fall back on records from nearby stations, adjusted according to typical seasonal and diurnal intra-station differences. For a given day of the year and hour of the day, the fallback station is selected to minimize the prediction error over the years for which there are measurements for both stations.
The stations on which we may fall back include but are not limited to Caldwell Industrial Airport; Boise Air Terminal; Ontario Municipal Airport; Mountain Home Air Force Base; McCall Airport; Rome State Airport; Stanley, Stanley Ranger Station; and Baker Municipal Airport.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Time zones for aiports and weather stations are provided by AskGeo.com .