August weather forecast
Key West, FL

August can be deemed as the most active month in terms of weather events in Key West. The intensity of sunlight during day time is counteracted by the occasional thunderstorms which bring respite from the heat. The constant weather changes can sometimes result in unfavorable conditions, but the tropical charm of the city remains intact. Along with the peak of hurricane season, the month offers the highest sea temperatures, peaking at 86.9°F, defining August's marine appeal.

Temperature

August temperatures tend to peak at an average high of 85.3°F and dip to a low of 82.9°F.

Heat index

Throughout August, the heat index is estimated at a torrid 95°F. Preventive measures are required to mitigate the risk of heat cramps and heat exhaustion. Continuous activity may precipitate heatstroke.
Consider that heat index readings are for situations in the shade and 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 'feels like' or 'apparent temperature', combines both the air temperature and the humidity level to give a perceived human temperature. One's weather perception can be influenced by a range of factors including metabolic differences, being pregnant, and their level of physical activity. In direct sunlight, the heat's impact can be heightened, potentially leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Young people are generally more susceptible than adults because they perspire less. Furthermore, their proportionally larger skin surface to their petite bodies and the increased heat output from their actions add to the risk.
Perspiration, followed by sweat evaporation, is the human body's chief method to maintain a balanced temperature. Under high air temperature and high humidity (high heat index) conditions, the body's ability to perspire is compromised, increasing the sensation of heat. Should the body fail to balance its heat gain, the escalating temperature poses health challenges.

Humidity

The months with the lowest humidity are July through September, with an average relative humidity of 74%.

Rainfall

In August, the rain falls for 23.1 days. Throughout August, 4.33" of precipitation is accumulated. Throughout the year, there are 199.2 rainfall days, and 31.61" of precipitation is accumulated.

Ocean temperature

August is the month with the warmest seawater, with an average ocean temperature of 86.9°F.
Note: When water's temperature exceeds 86°F, it arguably loses its primary appeal of offering a cool escape.

Daylight

In Key West, the average length of the day in August is 12h and 58min.
On the first day of August in Key West, sunrise is at 6:55 am and sunset at 8:11 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 7:46 pm EDT.

Sunshine

The average sunshine in August is 9.7h.

UV index

April through October, with an average maximum UV index of 7, are months with the highest UV index in Key West. A UV Index value of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for average individuals.
Note: An average UV index of 7 in August transforms into this advice:
Inhibit overexposure. Warding off sun damage is of utmost importance. The Sun's UV radiation is most potent between 10 a.m. and 4 p.m. Try to limit direct exposure to the Sun during this period. Always opt for UVA and UVB-resistant sunglasses on radiant days. Warning! The reflection of sand and water increases the UV dose.