August weather forecast
Key Largo, FL

The last month of the summer, August, is another warm month in Key Largo, Florida, with temperature in the range of an average high of 85.5°F (29.7°C) and an average low of 82.9°F (28.3°C).

Temperature

August is the warmest month, with an average high-temperature of 85.5°F (29.7°C) and an average low-temperature of 82.9°F (28.3°C).

Heat index

The average heat index in August is estimated at a torrid 95°F (35°C). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
Note that heat index values are valued for light wind and location in the shade. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like', 'apparent temperature', 'felt air temperature', or 'real feel', is calculated by taking the relative humidity value for a specific location and factoring it into the air temperature reading. Additional factors like activity, clothing, differences in body mass, height, and shape, and pregnancy affect individual temperature impact. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.
The human body cools itself through perspiration, as excessive warmth is removed from the body through sweat evaporation. Under high air temperature and humidity (high heat index) conditions, perspiration is limited, and the perception of heat is increased. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat-related illnesses and disorders may develop.

Humidity

The average relative humidity in August in Key Largo is 74%.

Rainfall

August is the month with the most rainfall in Key Largo. Rain falls for 20.9 days and accumulates 4.33" (110mm) of precipitation.

Ocean temperature

August is the month with the warmest seawater in Key Largo, with an average ocean temperature of 86.5°F (30.3°C).
Note: The surface water temperatures above 86°F (30°C) are arguably considered as unpleasant for swimming, and any intense water activity, as the refreshing effect of water is missing.

Daylight

The average length of the day in August is 12h and 59min.
On the first day of the month, sunrise is at 6:49 am and sunset at 8:07 pm. On the last day of August, in Key Largo, sunrise is at 7:02 am and sunset at 7:42 pm EDT.

Sunshine

In Key Largo, the average sunshine in August is 10.2h.

UV index

The months with the highest UV index in Key Largo are April through October, with an average maximum UV index of 7. A UV Index value of 6 to 7 symbolizes a high threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The daily maximum UV index of 7 in August interpret into the following advice:
Take precautions against overexposure. Protection against sun damage is needed. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.