Average Weather at Saint Paul Island Airport Alaska, United States

1. World
2. United States
3. Alaska
4. Aleutians West Census Area
5. Saint Paul Island Airport

At Saint Paul Island Airport, the summers are cold and windy; the winters are long, freezing, dry, and extremely windy; and it is overcast year round. Over the course of the year, the temperature typically varies from 21°F to 52°F and is rarely below 5°F or above 56°F.

The warm season lasts for 3.2 months, from June 21 to September 27, with an average daily high temperature above 47°F. The hottest day of the year is August 13, with an average high of 52°F and low of 46°F.

The cold season lasts for 4.1 months, from December 13 to April 15, with an average daily high temperature below 33°F. The coldest day of the year is February 11, with an average low of 21°F and high of 28°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 Saint Paul Island 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 Saint Paul Island Airport begins around September 2 and lasts for 2.7 months, ending around November 23. On October 7, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 37% of the time, and overcast or mostly cloudy 63% of the time.

The cloudier part of the year begins around November 23 and lasts for 9.3 months, ending around September 2. On July 13, the cloudiest day of the year, the sky is overcast or mostly cloudy 89% of the time, and clear, mostly clear, or partly cloudy 11% 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 Saint Paul Island Airport varies throughout the year.

The wetter season lasts 7.0 months, from July 19 to February 19, with a greater than 26% chance of a given day being a wet day. The chance of a wet day peaks at 36% on September 2.

The drier season lasts 5.0 months, from February 19 to July 19. The smallest chance of a wet day is 16% on May 8.

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 Saint Paul Island Airport changes throughout the year.

Rain alone is the most common for 9.7 months, from March 29 to January 18. The highest chance of a day with rain alone is 36% on September 2.

Snow alone is the most common for 2.3 months, from January 18 to March 29. The highest chance of a day with snow alone is 13% on February 11.

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. Saint Paul Island Airport experiences significant seasonal variation in monthly rainfall.

Rain falls throughout the year at Saint Paul Island Airport. The most rain falls during the 31 days centered around August 25, with an average total accumulation of 2.9 inches.

The least rain falls around March 19, with an average total accumulation of 0.6 inches.

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. Saint Paul Island Airport experiences some seasonal variation in monthly liquid-equivalent snowfall.

The snowy period of the year lasts for 6.1 months, from November 9 to May 11, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around February 9, with an average total liquid-equivalent accumulation of 0.8 inches.

The snowless period of the year lasts for 5.9 months, from May 11 to November 9. The least snow falls around August 5, with an average total liquid-equivalent accumulation of 0.0 inches.

The length of the day at Saint Paul Island Airport varies extremely over the course of the year. In 2017, the shortest day is December 21, with 6 hours, 40 minutes of daylight; the longest day is June 21, with 17 hours, 56 minutes of daylight.

The earliest sunrise is at 5:24 AM on June 18, and the latest sunrise is 4 hours, 36 minutes later at 10:00 AM on December 27. The earliest sunset is at 4:37 PM on December 14, and the latest sunset is 6 hours, 43 minutes later at 11:20 PM on June 23.

Daylight saving time (DST) is observed at Saint Paul 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 Saint Paul 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 Saint Paul Island Airport experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 7.3 months, from September 13 to April 23, with average wind speeds of more than 9.1 miles per hour. The windiest day of the year is January 29, with an average hourly wind speed of 11.8 miles per hour.

The calmer time of year lasts for 4.7 months, from April 23 to September 13. The calmest day of the year is July 15, with an average hourly wind speed of 6.5 miles per hour.

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

The wind is most often from the east for 3.1 weeks, from February 11 to March 5 and for 3.7 weeks, from June 6 to July 2, with a peak percentage of 37% on February 17. The wind is most often from the north for 3.0 months, from March 5 to June 6 and for 5.0 months, from September 11 to February 11, with a peak percentage of 41% on March 24. The wind is most often from the west for 2.3 months, from July 2 to September 11, with a peak percentage of 35% on August 8.

Saint Paul 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 15 to October 3, with an average temperature above 45°F. The day of the year with the warmest water is August 23, with an average temperature of 48°F.

The time of year with cooler water lasts for 4.5 months, from January 5 to May 21, with an average temperature below 37°F. The day of the year with the coolest water is March 25, with an average temperature of 34°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 significant seasonal variation over the course of the year.

The brighter period of the year lasts for 3.0 months, from April 22 to July 21, with an average daily incident shortwave energy per square meter above 3.7 kWh. The brightest day of the year is May 30, with an average of 4.7 kWh.

The darker period of the year lasts for 3.9 months, from October 22 to February 20, with an average daily incident shortwave energy per square meter below 1.1 kWh. The darkest day of the year is December 20, with an average of 0.2 kWh.

For the purposes of this report, the geographical coordinates of Saint Paul Island Airport are 57.158 deg latitude, -170.230 deg longitude, and 30 ft elevation.

The topography within 2 miles of Saint Paul Island Airport contains only modest variations in elevation, with a maximum elevation change of 371 feet and an average elevation above sea level of 58 feet. Within 10 miles contains only modest variations in elevation (610 feet). Within 50 miles contains significant variations in elevation (991 feet).

The area within 2 miles of Saint Paul Island Airport is covered by water (47%) and grassland (35%), within 10 miles by water (90%), and within 50 miles by water (99%).

This report illustrates the typical weather at Saint Paul 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

Saint Paul 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 St. George 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.