Average Weather in Pago Pago American Samoa
The climate in Pago Pago is hot, oppressive, windy, and overcast. Over the course of the year, the temperature typically varies from 77°F to 88°F and is rarely below 74°F or above 90°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
In Pago Pago, 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 Pago Pago begins around May 18 and lasts for 4.9 months, ending around October 15. On August 25, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 61% of the time, and overcast or mostly cloudy 39% of the time.
The cloudier part of the year begins around October 15 and lasts for 7.1 months, ending around May 18. On January 7, the cloudiest day of the year, the sky is overcast or mostly cloudy 88% of the time, and clear, mostly clear, or partly cloudy 12% 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 in Pago Pago varies significantly throughout the year.
The wetter season lasts 7.5 months, from October 10 to May 26, with a greater than 40% chance of a given day being a wet day. The chance of a wet day peaks at 63% on January 16.
The drier season lasts 4.5 months, from May 26 to October 10. The smallest chance of a wet day is 17% on July 29.
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 63% on January 16.
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. Pago Pago experiences extreme seasonal variation in monthly rainfall.
Rain falls throughout the year in Pago Pago. The most rain falls during the 31 days centered around January 21, with an average total accumulation of 10.2 inches.
The least rain falls around August 4, with an average total accumulation of 1.5 inches.
Average Monthly Rainfall
The length of the day in Pago Pago varies over the course of the year. In 2017, the shortest day is June 21, with 11 hours, 17 minutes of daylight; the longest day is December 21, with 12 hours, 59 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:43 AM on November 21, and the latest sunrise is 1 hour, 5 minutes later at 6:48 AM on July 9. The earliest sunset is at 6:00 PM on May 31, and the latest sunset is 58 minutes later at 6:58 PM on January 21.
Daylight saving time (DST) is not observed in Pago Pago during 2017.
Sunrise & Sunset with Twilight
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 in Pago Pago, 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, staying within 1% of 99% throughout.
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 in Pago Pago experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 5.4 months, from May 19 to October 30, with average wind speeds of more than 6.8 miles per hour. The windiest day of the year is July 29, with an average hourly wind speed of 8.1 miles per hour.
The calmer time of year lasts for 6.6 months, from October 30 to May 19. The calmest day of the year is March 9, with an average hourly wind speed of 5.6 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Pago Pago is from the east throughout the year.
Pago Pago 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 does not vary significantly over the course of the year, remaining within 2°F of 83°F throughout.
Average Water Temperature
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 some seasonal variation over the course of the year.
The brighter period of the year lasts for 2.2 months, from August 29 to November 6, with an average daily incident shortwave energy per square meter above 5.6 kWh. The brightest day of the year is September 20, with an average of 6.0 kWh.
The darker period of the year lasts for 3.0 months, from April 14 to July 14, with an average daily incident shortwave energy per square meter below 4.6 kWh. The darkest day of the year is May 29, with an average of 4.2 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Pago Pago are -14.278 deg latitude, -170.702 deg longitude, and 26 ft elevation.
The topography within 2 miles of Pago Pago contains very significant variations in elevation, with a maximum elevation change of 1,929 feet and an average elevation above sea level of 453 feet. Within 10 miles also contains very significant variations in elevation (1,932 feet). Within 50 miles also contains very significant variations in elevation (1,932 feet).
The area within 2 miles of Pago Pago is covered by trees (57%) and water (39%), within 10 miles by water (90%), and within 50 miles by water (100%).
This report illustrates the typical weather in Pago Pago, 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 2 weather stations near enough to contribute to our estimation of the temperature and dew point in Pago Pago.
For each station, the records are corrected for the elevation difference between that station and Pago Pago 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 Pago Pago is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Pago Pago and a given station.
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.