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Average Weather in Sigourney Iowa, United States

In Sigourney, the summers are long, warm, humid, 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 17°F to 86°F and is rarely below -2°F or above 95°F.

Based on the tourism score, the best time of year to visit Sigourney for warm-weather activities is from early June to mid September.

Climate Summary

very coldcoldcoolwarmhotwarmcoolcoldvery coldJanFebMarAprMayJunJulAugSepOctNovDec70%70%45%45%clearovercastprecipitation: 4.4 inprecipitation: 4.4 in0.7 in0.7 inmuggy: 57%muggy: 57%0%0%drydrytourism score: 6.5tourism score: 6.50.00.0
Click on each chart for more information.

Temperature

The hot season lasts for 4.0 months, from May 21 to September 20, with an average daily high temperature above 76°F. The hottest day of the year is July 18, with an average high of 86°F and low of 67°F.

The cold season lasts for 3.2 months, from November 29 to March 2, with an average daily high temperature below 43°F. The coldest day of the year is January 22, with an average low of 17°F and high of 33°F.

Average High and Low Temperature

The daily average high (red line) and low (blue line) temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.

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

Average Hourly Temperature in SigourneyJanFebMarAprMayJunJulAugSepOctNovDec12 AM4 AM8 AM12 PM4 PM8 PM12 AMfreezingcoldcoldcoolcoolcomfortablewarmfreezingvery cold
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The average hourly temperature, color coded into bands. The shaded overlays indicate night and civil twilight.

Bishkek, Kyrgyzstan (6,568 miles away) and Hwado, South Korea (6,444 miles) are the far-away foreign places with temperatures most similar to Sigourney (view comparison).

Clouds

In Sigourney, 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 Sigourney begins around June 10 and lasts for 4.5 months, ending around October 26. On September 14, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 70% of the time, and overcast or mostly cloudy 30% of the time.

The cloudier part of the year begins around October 26 and lasts for 7.5 months, ending around June 10. On February 9, the cloudiest day of the year, the sky is overcast or mostly cloudy 55% of the time, and clear, mostly clear, or partly cloudy 45% of the time.

Cloud Cover Categories

Cloud Cover Categories in SigourneyclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Sep 1470%Sep 1470%Feb 945%Feb 945%Jun 1057%Jun 1057%Oct 2658%Oct 2658%clearmostly clearpartly cloudymostly cloudyovercast
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds.

Precipitation

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

The wetter season lasts 5.7 months, from April 5 to September 27, with a greater than 26% chance of a given day being a wet day. The chance of a wet day peaks at 42% on June 26.

The drier season lasts 6.3 months, from September 27 to April 5. The smallest chance of a wet day is 10% on January 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 in Sigourney changes throughout the year.

Rain alone is the most common for 11 months, from February 2 to December 29. The highest chance of a day with rain alone is 42% on June 26.

Snow alone is the most common for 1.1 months, from December 29 to February 2. The highest chance of a day with snow alone is 6% on January 11.

Daily Chance of Precipitation

Daily Chance of Precipitation in SigourneysnowrainJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Jun 2642%Jun 2642%Jan 2810%Jan 2810%Dec 2913%Dec 2913%Apr 526%Apr 526%Sep 2726%Sep 2726%rainsnow
The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).

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. Sigourney experiences extreme seasonal variation in monthly rainfall.

The rainy period of the year lasts for 11 months, from February 2 to January 1, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around June 16, with an average total accumulation of 4.4 inches.

The rainless period of the year lasts for 1.0 months, from January 1 to February 2. The least rain falls around January 20, with an average total accumulation of 0.4 inches.

Average Monthly Rainfall

The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average liquid-equivalent snowfall.

Snowfall

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. Sigourney experiences some seasonal variation in monthly liquid-equivalent snowfall.

The snowy period of the year lasts for 4.1 months, from November 16 to March 20, 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 28, with an average total liquid-equivalent accumulation of 0.4 inches.

The snowless period of the year lasts for 7.9 months, from March 20 to November 16. The least snow falls around July 19, with an average total liquid-equivalent accumulation of 0.0 inches.

Average Liquid-Equivalent Monthly Snowfall

Average Liquid-Equivalent Monthly Snowfall in SigourneysnowsnowJanFebMarAprMayJunJulAugSepOctNovDec0 in1 in2 in3 in4 inDec 280.4 inDec 280.4 inJul 190.0 inJul 190.0 inMar 200.1 inMar 200.1 in
The average liquid-equivalent snowfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average rainfall.

Sun

The length of the day in Sigourney varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 11 minutes of daylight; the longest day is June 21, with 15 hours, 10 minutes of daylight.

Hours of Daylight and Twilight

The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.

The earliest sunrise is at 5:34 AM on June 14, and the latest sunrise is 2 hours, 8 minutes later at 7:42 AM on November 3. The earliest sunset is at 4:39 PM on December 8, and the latest sunset is 4 hours, 7 minutes later at 8:46 PM on June 27.

Daylight saving time (DST) is observed in Sigourney 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

Sunrise & Sunset with Twilight and Daylight Saving Time in SigourneyJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 145:34 AMJun 145:34 AM8:46 PMJun 278:46 PMJun 27Dec 84:39 PMDec 84:39 PM7:42 AMNov 37:42 AMNov 3Mar 11DSTMar 11DSTDSTNov 4DSTNov 4daynightnightnightnightSolarMidnightSolarMidnightSolarNoonSunriseSunset
The solar day over the course of the year 2018. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight saving time are indicated by the 'DST' labels.

Humidity

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.

Sigourney experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 3.6 months, from May 31 to September 17, during which time the comfort level is muggy, oppressive, or miserable at least 14% of the time. The muggiest day of the year is July 22, with muggy conditions 57% of the time.

The least muggy day of the year is December 10, when muggy conditions are essentially unheard of.

Humidity Comfort Levels

Humidity Comfort Levels in SigourneymuggyJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Dec 100%Dec 100%Jul 2257%Jul 2257%May 3114%May 3114%Sep 1714%Sep 1714%oppressiveoppressivemuggymuggydrydrycomfortablecomfortable
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The percentage of time spent at various humidity comfort levels, categorized by dew point.

Wind

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 Sigourney experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 7.7 months, from October 4 to May 25, with average wind speeds of more than 10.1 miles per hour. The windiest day of the year is April 1, with an average hourly wind speed of 12.5 miles per hour.

The calmer time of year lasts for 4.3 months, from May 25 to October 4. The calmest day of the year is August 3, with an average hourly wind speed of 7.7 miles per hour.

Average Wind Speed

Average Wind Speed in SigourneywindywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph2 mph4 mph6 mph8 mph10 mph12 mph14 mph16 mph18 mph20 mphApr 112.5 mphApr 112.5 mphAug 37.7 mphAug 37.7 mphOct 410.1 mphOct 410.1 mphMay 2510.1 mphMay 2510.1 mph
The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.

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

The wind is most often from the north for 2.5 months, from January 28 to April 13, with a peak percentage of 34% on February 19. The wind is most often from the south for 7.4 months, from April 13 to November 26, with a peak percentage of 41% on September 6. The wind is most often from the west for 2.1 months, from November 26 to January 28, with a peak percentage of 34% on January 1.

Wind Direction

Wind Direction in SigourneyWNSWJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%westsouthnortheast
northeastsouthwest
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions, excluding hours in which the mean wind speed is less than 1.0 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Best Time of Year to Visit

To characterize how pleasant the weather is in Sigourney 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 Sigourney for general outdoor tourist activities is from early June to mid September, with a peak score in the last week of August.

Tourism Score

Tourism Score in Sigourneybest timeJanFebMarAprMayJunJulAugSepOctNovDec02468106.56.50.00.0 precipitationprecipitationcloudscloudstemperaturetemperaturetourism score
The tourism score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

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 Sigourney for hot-weather activities is from late June to mid August, with a peak score in the third week of July.

Beach/Pool Score

Beach/Pool Score in Sigourneybest timeJanFebMarAprMayJunJulAugSepOctNovDec02468105.65.60.00.0 precipitationprecipitationcloudscloudstemperaturetemperaturebeach/pool score
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

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.

Growing Season

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 Sigourney typically lasts for 6.3 months (191 days), from around April 11 to around October 20, rarely starting before March 26 or after April 29, and rarely ending before October 1 or after November 7.

Time Spent in Various Temperature Bands and the Growing Season

Time Spent in Various Temperature Bands and the Growing Season in Sigourneygrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%50%Apr 1150%Apr 1150%Oct 2050%Oct 2090%Apr 2990%Apr 2990%Oct 190%Oct 110%Mar 2610%Mar 2610%Nov 710%Nov 70%Feb 40%Feb 4Jul 17100%Jul 17100%freezingvery coldcoolcomfortablewarmhotcold
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The percentage of time spent in various temperature bands. The black line is the percentage chance that a given day is within the growing season.

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 Sigourney should appear around April 6, only rarely appearing before March 23 or after April 22.

Growing Degree Days

Growing Degree Days in SigourneyJanFebMarAprMayJunJulAugSepOctNovDec0°F500°F1,000°F1,500°F2,000°F2,500°F3,000°F3,500°FApr 689°FApr 689°FJun 12900°FJun 12900°FJul 191,800°FJul 191,800°FDec 313,587°FDec 313,587°F
The average growing degree days accumulated over the course of the year, with 25th to 75th and 10th to 90th percentile bands.

Solar Energy

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 3.7 months, from May 2 to August 25, with an average daily incident shortwave energy per square meter above 5.9 kWh. The brightest day of the year is July 2, with an average of 6.9 kWh.

The darker period of the year lasts for 3.2 months, from November 2 to February 10, with an average daily incident shortwave energy per square meter below 2.8 kWh. The darkest day of the year is December 21, with an average of 1.8 kWh.

Average Daily Incident Shortwave Solar Energy

Average Daily Incident Shortwave Solar Energy in SigourneybrightdarkdarkJanFebMarAprMayJunJulAugSepOctNovDec0 kWh1 kWh2 kWh3 kWh4 kWh5 kWh6 kWh7 kWh8 kWh9 kWhJul 26.9 kWhJul 26.9 kWhDec 211.8 kWhDec 211.8 kWhMay 25.9 kWhMay 25.9 kWhAug 255.9 kWhAug 255.9 kWhFeb 102.8 kWhFeb 102.8 kWh
The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

Topography

For the purposes of this report, the geographical coordinates of Sigourney are 41.333 deg latitude, -92.205 deg longitude, and 732 ft elevation.

The topography within 2 miles of Sigourney contains only modest variations in elevation, with a maximum elevation change of 135 feet and an average elevation above sea level of 726 feet. Within 10 miles also contains only modest variations in elevation (279 feet). Within 50 miles contains only modest variations in elevation (502 feet).

The area within 2 miles of Sigourney is covered by cropland (92%), within 10 miles by cropland (92%), and within 50 miles by cropland (88%).

Data Sources

This report illustrates the typical weather in Sigourney, 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 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Sigourney.

For each station, the records are corrected for the elevation difference between that station and Sigourney 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 Sigourney is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Sigourney and a given station.

The stations contributing to this reconstruction are: Oskaloosa Municipal Airport (42%, 27 kilometers, southwest); Fairfield Municipal Airport (26%, 36 kilometers, southeast); Washington Municipal Airport (19%, 45 kilometers, east); and Grinnell Regional Airport (13%, 59 kilometers, northwest).

Other Data

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.

Disclaimer

The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.

We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.

We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.