September weather forecast
Port Royal, SC

September marks the beginning of a gradual transition from summer to fall in Port Royal. The temperatures start to cool down slightly, with averages ranging between 72.5°F (22.5°C) and 85.1°F (29.5°C). Moreover, daylight hours start to shorten, with an average of 12.4 hours per day. Even though temperatures begin to drop, weather remains warm enough for swimming and other water activities until the end of September.

Temperature

September in Port Royal registers an average high-temperature of a warm 85.1°F (29.5°C), slightly varied from August's 88.9°F (31.6°C). Port Royal experiences a steady low-temperature of 72.5°F (22.5°C) throughout September.

Heat index

September's mean heat index is estimated at a very hot 95°F (35°C). Exercise increased caution, heat cramps and heat exhaustion are potential hazards. Continuous activity could lead to heatstroke.
Keep in mind the heat index values are meant for areas in shade and with light wind. The direct sun can potentially cause the heat index to increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', melds the effects of warmth and moisture to generate a feeling of heat. The perception of temperature can be subjective, varying based on activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. Keep in mind that direct sunshine exposure can amplify the weather's effects, possibly increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for babies and toddlers. Younglings frequently fail to recognize the requirement to rest and rehydrate. Thirst emerges late in dehydration - it is imperative to keep hydration levels high, particularly during extended physical exertions.
When it comes to cooling down, the human body's primary method is through perspiration, making use of sweat evaporation to eliminate excess heat. In the presence of elevated relative humidity, the evaporation rate decreases. This reduction leads to increased body heat retention compared to conditions of dry air. Rising body temperatures resulting from an imbalance in heat absorption can lead to potential thermal issues.

Humidity

The average relative humidity in September is 75%.

Rainfall

In Port Royal, South Carolina, in September, it is raining for 14.9 days, with typically 2.28" (58mm) of accumulated precipitation. Throughout the year, there are 154.7 rainfall days, and 23.11" (587mm) of precipitation is accumulated.

Snowfall

In Port Royal, South Carolina, snow does not fall in March through November.

Daylight

The average length of the day in September in Port Royal is 12h and 22min.
On the first day of September in Port Royal, South Carolina, sunrise is at 6:58 am and sunset at 7:46 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 7:08 pm EDT.

Sunshine

In Port Royal, the average sunshine in September is 8.7h.

UV index

In Port Royal, the average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high health hazard from exposure to the Sun's UV radiation for average individuals.
Note: The maximum daily UV index of 6 in September interprets into the following recommendations:
Apply measures and align with sun safety principles. Safeguarding against skin and eye injury is pivotal. Attempt to stay under shade and limit exposure to the Sun between 10 a.m. and 4 p.m., when UV radiation is at its peak. Remember, devices such as parasols or canopies might not provide complete sun protection. Enhance your sun protection with tightly woven, yet airy clothing.