Average Weather at Iowa County Airport Wisconsin, United States
At Iowa County Airport, the summers are long, warm, and wet; the winters are freezing, dry, and windy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 14°F to 82°F and is rarely below -7°F or above 90°F.
The warm season lasts for 4.0 months, from May 20 to September 20, with an average daily high temperature above 71°F. The hottest day of the year is July 19, with an average high of 82°F and low of 64°F.
The cold season lasts for 3.2 months, from November 29 to March 4, with an average daily high temperature below 39°F. The coldest day of the year is January 22, with an average low of 14°F and high of 28°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 Iowa County 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 Iowa County Airport begins around June 6 and lasts for 4.6 months, ending around October 25. On August 26, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 69% of the time, and overcast or mostly cloudy 31% of the time.
The cloudier part of the year begins around October 25 and lasts for 7.4 months, ending around June 6. On December 29, 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
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at Iowa County Airport varies throughout the year.
The wetter season lasts 5.9 months, from April 5 to October 3, with a greater than 26% chance of a given day being a wet day. The chance of a wet day peaks at 39% on June 10.
The drier season lasts 6.1 months, from October 3 to April 5. The smallest chance of a wet day is 12% on February 11.
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 at Iowa County Airport changes throughout the year.
Rain alone is the most common for 9.8 months, from February 19 to December 15. The highest chance of a day with rain alone is 39% on June 10.
Snow alone is the most common for 2.2 months, from December 15 to February 19. The highest chance of a day with snow alone is 8% on January 12.
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. Iowa County Airport experiences significant seasonal variation in monthly rainfall.
The rainy period of the year lasts for 11 months, from February 10 to December 31, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around June 15, with an average total accumulation of 4.2 inches.
The rainless period of the year lasts for 1.4 months, from December 31 to February 10. The least rain falls around January 21, 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. Iowa County Airport experiences some seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 4.7 months, from November 12 to April 4, 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 21, with an average total liquid-equivalent accumulation of 0.4 inches.
The snowless period of the year lasts for 7.3 months, from April 4 to November 12. The least snow falls around July 31, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
The length of the day at Iowa County Airport varies significantly over the course of the year. In 2017, the shortest day is December 21, with 9 hours, 1 minute of daylight; the longest day is June 20, with 15 hours, 21 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:21 AM on June 15, and the latest sunrise is 2 hours, 18 minutes later at 7:39 AM on November 4. The earliest sunset is at 4:26 PM on December 9, and the latest sunset is 4 hours, 17 minutes later at 8:43 PM on June 26.
Daylight saving time (DST) is observed at Iowa County Airport during 2017, starting in the spring on March 12, lasting 7.8 months, and ending in the fall on November 5.
Sunrise & Sunset with Twilight and Daylight Saving Time
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.
Iowa County Airport experiences significant seasonal variation in the perceived humidity.
The muggier period of the year lasts for 3.5 months, from June 4 to September 18, during which time the comfort level is muggy, oppressive, or miserable at least 10% of the time. The muggiest day of the year is July 22, with muggy conditions 38% of the time.
The least muggy day of the year is February 15, when muggy conditions are essentially unheard of.
Humidity Comfort Levels
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 at Iowa County Airport experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 7.8 months, from September 30 to May 23, with average wind speeds of more than 5.4 miles per hour. The windiest day of the year is March 23, with an average hourly wind speed of 6.7 miles per hour.
The calmer time of year lasts for 4.2 months, from May 23 to September 30. The calmest day of the year is August 3, with an average hourly wind speed of 4.2 miles per hour.
Average Wind Speed
The predominant average hourly wind direction at Iowa County Airport varies throughout the year.
The wind is most often from the north for 2.3 months, from February 10 to April 18, with a peak percentage of 33% on March 8. The wind is most often from the south for 6.8 months, from April 26 to November 21, with a peak percentage of 39% on September 6. The wind is most often from the west for 2.6 months, from November 21 to February 10, with a peak percentage of 36% on January 1.
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 3.5 months, from May 5 to August 21, with an average daily incident shortwave energy per square meter above 5.9 kWh. The brightest day of the year is July 1, with an average of 7.0 kWh.
The darker period of the year lasts for 3.4 months, from October 30 to February 11, with an average daily incident shortwave energy per square meter below 2.7 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 Iowa County Airport are 42.888 deg latitude, -90.228 deg longitude, and 1,073 ft elevation.
The topography within 2 miles of Iowa County Airport contains only modest variations in elevation, with a maximum elevation change of 305 feet and an average elevation above sea level of 1,075 feet. Within 10 miles contains only modest variations in elevation (535 feet). Within 50 miles contains significant variations in elevation (1,125 feet).
The area within 2 miles of Iowa County Airport is covered by cropland (94%), within 10 miles by cropland (86%) and trees (13%), and within 50 miles by cropland (66%) and trees (29%).
This report illustrates the typical weather at Iowa County 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
Iowa County 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 Platteville Municipal Airport, Tri-County Regional Airport, Boscobel Airport, Dubuque Regional Airport, Monroe Municipal Airport, Baraboo Wisconsin Dells Airport, Tri-Township Airport, and Prairie du Chien Municipal Airport.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
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.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.