Average Weather in September in Kotzebue Alaska, United States
In Kotzebue, the month of September is characterized by rapidly falling daily high temperatures, with daily highs decreasing by 13°F, from 53°F to 40°F over the course of the month, and rarely exceeding 60°F or dropping below 33°F.
Daily low temperatures decrease by 12°F, from 44°F to 32°F, rarely falling below 23°F or exceeding 51°F.
For reference, on July 15, the hottest day of the year, temperatures in Kotzebue typically range from 51°F to 60°F, while on January 20, the coldest day of the year, they range from -8°F to 4°F.
Average High and Low Temperature in September
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on September. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature in September
The month of September in Kotzebue experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 57% throughout the month.
The clearest day of the month is September 25, with clear, mostly clear, or partly cloudy conditions 44% of the time.
For reference, on January 10, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 67%, while on May 29, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 45%.
Cloud Cover Categories in September
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Kotzebue, the chance of a wet day over the course of September is very rapidly decreasing, starting the month at 28% and ending it at 20%.
For reference, the year's highest daily chance of a wet day is 32% on August 11, and its lowest chance is 6% on March 19.
Over the course of September in Kotzebue, the chance of a day with only rain decreases from 28% to 17%, the chance of a day with mixed snow and rain remains an essentially constant 1% throughout, and the chance of a day with only snow remains an essentially constant 1% throughout.
Probability of Precipitation in September
To show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day rainfall during September in Kotzebue is decreasing, starting the month at 2.1 inches, when it rarely exceeds 3.6 inches or falls below 0.8 inches, and ending the month at 1.2 inches, when it rarely exceeds 2.1 inches or falls below 0.2 inches.
Average Monthly Rainfall in September
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. As with rainfall, we consider the liquid-equivalent snowfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day liquid-equivalent snowfall during September in Kotzebue is essentially constant, remaining about 0.1 inches throughout, and rarely exceeding 0.3 inches or falling below -0.0 inches.
Average Monthly Liquid-Equivalent Snowfall in September
Due to its extreme latitude, Kotzebue experiences polar day (also known as the midnight Sun) during the summer. The precise start and end dates of polar day and night vary from year to year and depend on the precise location and elevation of the observer, and the local topography.
Neither polar day nor polar night occur during the month of September.
Over the course of September in Kotzebue, the length of the day is very rapidly decreasing. From the start to the end of the month, the length of the day decreases by 3 hours, 33 minutes, implying an average daily decrease of 7 minutes, 21 seconds, and weekly decrease of 51 minutes, 28 seconds.
The shortest day of the month is September 30, with 11 hours, 18 minutes of daylight and the longest day is September 1, with 14 hours, 51 minutes of daylight.
Hours of Daylight and Twilight in September
The earliest sunrise of the month in Kotzebue is 7:23 AM on September 1 and the latest sunrise is 1 hour, 37 minutes later at 9:00 AM on September 30.
The latest sunset is 10:14 PM on September 1 and the earliest sunset is 1 hour, 56 minutes earlier at 8:18 PM on September 30.
Daylight saving time is observed in Kotzebue during 2017, but it neither starts nor ends during September, so the entire month is in daylight saving time.
Sunrise & Sunset with Twilight in September
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 chance that a given day will be muggy in Kotzebue is essentially constant during September, remaining around 0% throughout.
For reference, on June 24, the muggiest day of the year, there are muggy conditions 0% of the time, while on January 1, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in September
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 Kotzebue is gradually increasing during September, increasing from 5.5 miles per hour to 6.4 miles per hour over the course of the month.
For reference, on December 30, the windiest day of the year, the daily average wind speed is 8.0 miles per hour, while on June 19, the calmest day of the year, the daily average wind speed is 3.9 miles per hour.
Average Wind Speed in September
Wind Direction in September
Kotzebue is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average surface water temperature in Kotzebue is rapidly decreasing during September, falling by 8°F, from 49°F to 41°F, over the course of the month.
Average Water Temperature in September
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 in Kotzebue is decreasing during September, falling by 1.5 kWh, from 2.9 kWh to 1.5 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in September
For the purposes of this report, the geographical coordinates of Kotzebue are 66.898 deg latitude, -162.598 deg longitude, and 0 ft elevation.
The topography within 2 miles of Kotzebue contains only modest variations in elevation, with a maximum elevation change of 121 feet and an average elevation above sea level of 13 feet. Within 10 miles also contains only modest variations in elevation (305 feet). Within 50 miles contains only modest variations in elevation (3,130 feet).
The area within 2 miles of Kotzebue is covered by water (73%), sparse vegetation (13%), and shrubs (11%), within 10 miles by water (67%) and shrubs (17%), and within 50 miles by water (53%) and shrubs (23%).
This report illustrates the typical weather in Kotzebue year round, 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 Kotzebue.
For each station, the records are corrected for the elevation difference between that station and Kotzebue 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 Kotzebue is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Kotzebue and a given station.
The stations contributing to this reconstruction are: Ralph Wien Memorial Airport (98%, 3.8 kilometers, southwest); Robert (Bob) Curtis Memorial Airport (1.3%, 70 kilometers, east); and Noatak Airport (1.1%, 76 kilometers, north).
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.