Average Weather at Middleton Island Airport Alaska, United States

1. World
2. United States
3. Alaska
4. Valdez-Cordova Census Area
5. Middleton Island Airport

At Middleton Island Airport, the summers are short, cool, and windy; the winters are long, chilly, and extremely windy; and it is wet and mostly cloudy year round. Over the course of the year, the temperature typically varies from 33°F to 59°F and is rarely below 24°F or above 64°F.

The warm season lasts for 2.9 months, from June 20 to September 17, with an average daily high temperature above 55°F. The hottest day of the year is August 1, with an average high of 59°F and low of 53°F.

The cool season lasts for 4.9 months, from November 11 to April 7, with an average daily high temperature below 43°F. The coldest day of the year is March 2, with an average low of 33°F and high of 39°F.

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.

At Middleton Island Airport, the average percentage of the sky covered by clouds experiences mild seasonal variation over the course of the year.

The clearer part of the year at Middleton Island Airport begins around June 16 and lasts for 5.1 months, ending around November 19. On August 24, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 40% of the time, and overcast or mostly cloudy 60% of the time.

The cloudier part of the year begins around November 19 and lasts for 6.9 months, ending around June 16. On January 26, the cloudiest day of the year, the sky is overcast or mostly cloudy 75% of the time, and clear, mostly clear, or partly cloudy 25% of the time.

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

The wetter season lasts 6.5 months, from August 22 to March 7, with a greater than 40% chance of a given day being a wet day. The chance of a wet day peaks at 53% on October 4.

The drier season lasts 5.5 months, from March 7 to August 22. The smallest chance of a wet day is 26% on July 7.

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 53% on October 4.

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. Middleton Island Airport experiences extreme seasonal variation in monthly rainfall.

Rain falls throughout the year at Middleton Island Airport. The most rain falls during the 31 days centered around October 1, with an average total accumulation of 6.7 inches.

The least rain falls around June 24, with an average total accumulation of 2.2 inches.

Snowfall

The sliding 31-day liquid-equivalent quantity of snowfall at Middleton Island Airport does not vary significantly over the course of the year, staying within 0.1 inches of 0.1 inches throughout.

The length of the day at Middleton Island Airport varies extremely over the course of the year. In 2017, the shortest day is December 21, with 6 hours, 3 minutes of daylight; the longest day is June 21, with 18 hours, 40 minutes of daylight.

The earliest sunrise is at 4:26 AM on June 18, and the latest sunrise is 5 hours, 17 minutes later at 9:43 AM on December 27. The earliest sunset is at 3:43 PM on December 15, and the latest sunset is 7 hours, 24 minutes later at 11:07 PM on June 21.

Daylight saving time (DST) is observed at Middleton Island Airport during 2017, starting in the spring on March 12, lasting 7.8 months, and ending in the fall on November 5.

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 perceived humidity level at Middleton Island 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.

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 Middleton Island Airport experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 7.1 months, from September 13 to April 16, with average wind speeds of more than 8.0 miles per hour. The windiest day of the year is January 8, with an average hourly wind speed of 10.5 miles per hour.

The calmer time of year lasts for 4.9 months, from April 16 to September 13. The calmest day of the year is July 17, with an average hourly wind speed of 5.6 miles per hour.

The predominant average hourly wind direction at Middleton Island Airport varies throughout the year.

The wind is most often from the west for 2.0 months, from June 23 to August 22, with a peak percentage of 38% on July 7. The wind is most often from the south for 1.5 months, from August 22 to October 5, with a peak percentage of 32% on September 18. The wind is most often from the east for 8.6 months, from October 5 to June 23, with a peak percentage of 40% on January 1.

Middleton Island Airport 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 water temperature experiences some seasonal variation over the course of the year.

The time of year with warmer water lasts for 2.6 months, from July 2 to September 19, with an average temperature above 53°F. The day of the year with the warmest water is August 10, with an average temperature of 56°F.

The time of year with cooler water lasts for 4.7 months, from December 16 to May 8, with an average temperature below 44°F. The day of the year with the coolest water is March 9, with an average temperature of 41°F.

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 3.0 months, from May 8 to August 7, with an average daily incident shortwave energy per square meter above 4.4 kWh. The brightest day of the year is June 20, with an average of 5.5 kWh.

The darker period of the year lasts for 4.4 months, from October 15 to February 27, with an average daily incident shortwave energy per square meter below 1.3 kWh. The darkest day of the year is December 21, with an average of 0.2 kWh.

For the purposes of this report, the geographical coordinates of Middleton Island Airport are 59.450 deg latitude, -146.309 deg longitude, and 0 ft elevation.

The topography within 2 miles of Middleton Island Airport contains only modest variations in elevation, with a maximum elevation change of 118 feet and an average elevation above sea level of 9 feet. Within 10 miles also contains only modest variations in elevation (135 feet). Within 50 miles also contains only modest variations in elevation (210 feet).

The area within 2 miles of Middleton Island Airport is covered by water (81%) and shrubs (12%), within 10 miles by water (99%), and within 50 miles by water (100%).

This report illustrates the typical weather at Middleton Island 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

Middleton Island 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.

In this case, the only station close and reliable enough to use as a fallback is Merle K. (Mudhole) Smith Airport.

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.