May weather forecast and climate
Key Biscayne, FL

The beautiful and dramatic landscape of the Miami Crandon Park in Key Biscayne, Florida
The beautiful and dramatic landscape of the Miami Crandon Park in Key Biscayne, Florida

Weather in May

The last month of the spring, May, is another warm month in Key Biscayne, Florida, with average temperature fluctuating between 82°F (27.8°C) and 77°F (25°C).

Temperature

In May, the average high-temperature is essentially the same as in April - a still moderately hot 82°F (27.8°C). The average low-temperature, in Key Biscayne, is 77°F (25°C).

Heat index

In May, the average heat index is calculated to be a tropical 86.9°F (30.5°C). Constant exposure and activity lead to possible fatigue. Prolonged exercise may result in heat cramps.
Note that heat index values are valued for light wind and location in the shade. With exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel', 'feels like', 'felt air temperature', or 'apparent temperature', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. Additional factors like clothing, metabolic differences, pregnancy, and activity influence one's weather impression. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. 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.

Humidity

In May, the average relative humidity is 72%.

Rainfall

In May, the rain falls for 15.3 days. Throughout May, 1.77" (45mm) of precipitation is accumulated. In Key Biscayne, during the entire year, the rain falls for 182.7 days and collects up to 16.38" (416mm) of precipitation.

Ocean temperature

In May, the average ocean temperature in Key Biscayne is 81.1°F (27.3°C).
Note: For swimming, diving, and other water activities, temperatures between 77°F (25°C) and 84.2°F (29°C) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

Daylight

The average length of the day in Key Biscayne is 13.4h.

Sunshine

In May, the average sunshine is 10.7h.

UV index

May through October, with an average maximum UV index of 7, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health risk from unprotected exposure to the Sun's UV rays for the ordinary person.
Note: The average daily UV index of 7 transform into the following instructions:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. 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. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.
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FAQ

What is the temperature in May in Key Biscayne?

In Key Biscayne, Florida, in May, the average high-temperature is 82°F (27.8°C), and the average low-temperature is 77°F (25°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, in May is calculated to be 86.9°F (30.5°C).

What is the average humidity in May in Key Biscayne?

The average relative humidity in May in Key Biscayne, Florida, is 72%.

How many days does it rain in May in Key Biscayne?

In Key Biscayne, in May, during 15.3 rainfall days, 1.77" (45mm) of precipitation is typically accumulated.

What is the water temperature in May in Key Biscayne?

In Key Biscayne, Florida, in May, the average water temperature is 81.1°F (27.3°C). For any water activity, surface water temperatures between 77°F (25°C) and 84.2°F (29°C) are considered as excellent and extremely pleasant for lengthened periods.

What is the average length of the day in May in Key Biscayne?

In May, the average length of the day is 13.4h.

How many hours of sunshine does Key Biscayne have in May?

The average sunshine in May in Key Biscayne, Florida, is 10.7h.

What are the months with the highest UV index in Key Biscayne?

May through October, with an average maximum UV index of 7, are months with the highest UV index.

What is the UV index reading in May in Key Biscayne?

In May, the average daily maximum UV index is 7. A UV Index of 6 to 7 symbolizes a high health risk from the exposure to the Sun's UV rays.

Average temperature in May
Key Biscayne, FL

Average temperature in May - Key Biscayne, FL
  • Average high temperature in May: 82°F

The warmest month (with the highest average high temperature) is August (87.1°F).
The month with the lowest average high temperature is January (73°F).

  • Average low temperature in May: 77°F

The month with the highest average low temperature is August (82.6°F).
The coldest month (with the lowest average low temperature) is January (65.1°F).

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Average pressure in May
Key Biscayne, FL

Average pressure in May - Key Biscayne, FL
  • Average pressure in May: 30.01"

The month with the highest atmospheric pressure is January (30.11").
Months with the lowest atmospheric pressure are September and October (29.95").

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Average wind speed in May
Key Biscayne, FL

Average wind speed in May - Key Biscayne, FL
  • Average wind speed in May: 10.6mph

The windiest month (with the highest average wind speed) is March (11.6mph).
The calmest month (with the lowest average wind speed) is July (8.1mph).

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Average humidity in May
Key Biscayne, FL

Average humidity in May - Key Biscayne, FL
  • Average humidity in May: 72%

The month with the highest relative humidity is December (75%).
The month with the lowest relative humidity is March (70%).

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Average rainfall in May
Key Biscayne, FL

Average rainfall in May - Key Biscayne, FL
  • Average rainfall in May: 1.77"

The wettest month (with the highest rainfall) is August (2.8").
The driest month (with the least rainfall) is January (0.43").

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Average rainfall days in May
Key Biscayne, FL

Average rainfall days in May - Key Biscayne, FL
  • Average rainfall days in May: 15.3 days

The month with the highest number of rainy days is September (24.5 days).
The month with the least rainy days is February (8.7 days).

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Average sea temperature in May
Key Biscayne, FL

Average sea temperature in May - Key Biscayne, FL
  • Average sea temperature in May: 81.1°F

The best month for swimming (with the highest average sea temperature) is August (86.5°F).
The coldest month (with the lowest average sea temperature) is February (74°F).

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Average daylight in May /
Average sunshine in May
Key Biscayne, FL

Average daylight in May / Average sunshine in May - Key Biscayne, FL
  • Average daylight in May: 13.4h

The month with the longest days is June (Average daylight: 13.7h).
The month with the shortest days is December (Average daylight: 10.6h).

  • Average sunshine in May: 10.7h

The month with the most sunshine is July (Average sunshine: 11.1h).
The month with the least sunshine is December (Average sunshine: 6.4h).

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Average sunshine days in May
Key Biscayne, FL

Average sunshine days in May - Key Biscayne, FL
  • Average sunshine days in May: 11.4 days

The month with the most sunshine days is March (17 days).
The month with the least sunshine days is September (3.2 days).

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Average UV index in May
Key Biscayne, FL

Average UV index in May - Key Biscayne, FL
  • Average UV index in May: 7

Months with the highest UV index are May, June, July, August, September and October (UV index 7).
Months with the lowest UV index are January and December (UV index 5).

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Average cloud cover in May
Key Biscayne, FL

Average cloud cover in May - Key Biscayne, FL
  • Average cloud cover in May: 28

The month with the most cloud cover is October (Cloud cover 35).
The month with the least cloud cover is April (Cloud cover 26).

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Average visibility in May
Key Biscayne, FL

Average visibility in May - Key Biscayne, FL
  • Average visibility in May: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

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