Climate and Average Weather Year Round at Harry P Williams Memorial Airport United States

At Harry P Williams Memorial Airport, the summers are long, hot, and oppressive; the winters are short, cool, and windy; and it is wet and partly cloudy year round. Over the course of the year, the temperature typically varies from 45°F to 90°F and is rarely below 31°F or above 94°F.

Based on the tourism score, the best times of year to visit Harry P Williams Memorial Airport for warm-weather activities are from late March to mid May and from late September to late October.

The hot season lasts for 4.2 months, from May 18 to September 26, with an average daily high temperature above 84°F. The hottest month of the year at Harry P Williams Memorial Airport is July, with an average high of 89°F and low of 74°F.

The cool season lasts for 2.8 months, from December 1 to February 25, with an average daily high temperature below 68°F. The coldest month of the year at Harry P Williams Memorial Airport is January, with an average low of 45°F and high of 63°F.

At Harry P Williams Memorial 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 Harry P Williams Memorial Airport begins around September 13 and lasts for 9.1 months, ending around June 17.

The clearest month of the year at Harry P Williams Memorial Airport is October, during which on average the sky is clear, mostly clear, or partly cloudy 65% of the time.

The cloudier part of the year begins around June 17 and lasts for 2.9 months, ending around September 13.

The cloudiest month of the year at Harry P Williams Memorial Airport is July, during which on average the sky is overcast or mostly cloudy 57% 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 Harry P Williams Memorial Airport varies significantly throughout the year.

The wetter season lasts 3.3 months, from June 2 to September 11, with a greater than 41% chance of a given day being a wet day. The month with the most wet days at Harry P Williams Memorial Airport is July, with an average of 18.2 days with at least 0.04 inches of precipitation.

The drier season lasts 8.7 months, from September 11 to June 2. The month with the fewest wet days at Harry P Williams Memorial Airport is October, with an average of 7.6 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone at Harry P Williams Memorial Airport is July, with an average of 18.2 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 60% on July 7.

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. Harry P Williams Memorial Airport experiences significant seasonal variation in monthly rainfall.

Rain falls throughout the year at Harry P Williams Memorial Airport. The month with the most rain at Harry P Williams Memorial Airport is June, with an average rainfall of 5.5 inches.

The month with the least rain at Harry P Williams Memorial Airport is October, with an average rainfall of 3.7 inches.

The length of the day at Harry P Williams Memorial Airport varies significantly over the course of the year. In 2024, the shortest day is December 21, with 10 hours, 14 minutes of daylight; the longest day is June 20, with 14 hours, 3 minutes of daylight.

The earliest sunrise is at 6:04 AM on June 10, and the latest sunrise is 1 hour, 16 minutes later at 7:20 AM on March 10. The earliest sunset is at 5:05 PM on December 1, and the latest sunset is 3 hours, 4 minutes later at 8:09 PM on June 30.

Daylight saving time (DST) is observed at Harry P Williams Memorial Airport during 2024, starting in the spring on March 10, lasting 7.8 months, and ending in the fall on November 3.

The figure below presents a compact representation of key lunar data for 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

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.

Harry P Williams Memorial Airport experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 6.3 months, from April 15 to October 25, during which time the comfort level is muggy, oppressive, or miserable at least 28% of the time. The month with the most muggy days at Harry P Williams Memorial Airport is July, with 30.3 days that are muggy or worse.

The month with the fewest muggy days at Harry P Williams Memorial Airport is January, with 1.6 days that are muggy or worse.

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 Harry P Williams Memorial Airport experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 7.9 months, from September 26 to May 21, with average wind speeds of more than 9.1 miles per hour. The windiest month of the year at Harry P Williams Memorial Airport is February, with an average hourly wind speed of 11.3 miles per hour.

The calmer time of year lasts for 4.1 months, from May 21 to September 26. The calmest month of the year at Harry P Williams Memorial Airport is August, with an average hourly wind speed of 6.9 miles per hour.

The predominant average hourly wind direction at Harry P Williams Memorial Airport varies throughout the year.

The wind is most often from the south for 5.0 months, from February 21 to July 20 and for 2.0 weeks, from August 8 to August 22, with a peak percentage of 54% on June 3. The wind is most often from the east for 2.9 months, from August 22 to November 19, with a peak percentage of 44% on September 19. The wind is most often from the north for 3.1 months, from November 19 to February 21, with a peak percentage of 37% on January 1.

Harry P Williams Memorial 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 significant seasonal variation over the course of the year.

The time of year with warmer water lasts for 3.9 months, from May 30 to September 26, with an average temperature above 81°F. The month of the year at Harry P Williams Memorial Airport with the warmest water is August, with an average temperature of 85°F.

The time of year with cooler water lasts for 3.3 months, from December 7 to March 17, with an average temperature below 66°F. The month of the year at Harry P Williams Memorial Airport with the coolest water is January, with an average temperature of 61°F.

To characterize how pleasant the weather is at Harry P Williams Memorial Airport 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 times of year to visit Harry P Williams Memorial Airport for general outdoor tourist activities are from late March to mid May and from late September to late October, with a peak score in the last week of April.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best times of year to visit Harry P Williams Memorial Airport for hot-weather activities are from early May to late June and from late August to late September, with a peak score in the first week of June.

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.

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 at Harry P Williams Memorial Airport typically lasts for 10 months (317 days), from around February 5 to around December 18, rarely starting after March 6, or ending before November 23.

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 at Harry P Williams Memorial Airport should appear around January 16, only rarely appearing before January 10 or after January 28.

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 2.6 months, from March 30 to June 19, with an average daily incident shortwave energy per square meter above 5.9 kWh. The brightest month of the year at Harry P Williams Memorial Airport is May, with an average of 6.5 kWh.

The darker period of the year lasts for 2.5 months, from November 15 to February 1, with an average daily incident shortwave energy per square meter below 3.8 kWh. The darkest month of the year at Harry P Williams Memorial Airport is December, with an average of 3.1 kWh.

For the purposes of this report, the geographical coordinates of Harry P Williams Memorial Airport are 29.712 deg latitude, -91.334 deg longitude, and 3 ft elevation.

The topography within 2 miles of Harry P Williams Memorial Airport is essentially flat, with a maximum elevation change of 10 feet and an average elevation above sea level of 4 feet. Within 10 miles is also essentially flat (39 feet). Within 50 miles is essentially flat (141 feet).

The area within 2 miles of Harry P Williams Memorial Airport is covered by cropland (49%) and herbaceous vegetation (49%), within 10 miles by herbaceous vegetation (79%) and cropland (12%), and within 50 miles by herbaceous vegetation (50%) and water (33%).