May weather in Key Biscayne, FL
The average temperature in Key Biscayne in May is 80.7°F (74.9°F–86.5°F). Average precipitation: 5.67 inches.
May is a spring month in Key Biscayne, and is warmer than the annual average of 78.7°F. Daily temperatures swing about 11.6°F between overnight low and afternoon high. Expect about 10 days with precipitation. Daylight averages about 13h 15m. For travel, May is a wet month.
Avg High
86.5°F
Avg Low
74.9°F
Precipitation
5.67 in
Daylight
13h 15m
May records in Key Biscayne
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| May 1 | 89.1°F (2014) | 64.9°F (2020) | 1.17 in (2003) |
| May 2 | 89.1°F (2021) | 66.0°F (2006) | 0.63 in (1998) |
| May 3 | 89.1°F (2014) | 66.9°F (2006) | 1.26 in (2013) |
| May 4 | 90.0°F (2014) | 64.9°F (2001) | 3.31 in (2001) |
| May 5 | 89.1°F (2019) | 66.9°F (2023) | 2.04 in (2016) |
| May 6 | 90.0°F (2019) | 63.0°F (2013) | 2.29 in (2011) |
| May 7 | 90.0°F (2021) | 63.0°F (2017) | 3.24 in (2011) |
| May 8 | 91.9°F (2022) | 62.1°F (2013) | 1.88 in (2021) |
| May 9 | 91.0°F (2022) | 64.9°F (2013) | 0.56 in (2022) |
| May 10 | 88.0°F (2019) | 61.0°F (2001) | 3.55 in (2012) |
| May 11 | 90.0°F (2012) | 64.9°F (2017) | 0.34 in (2020) |
| May 12 | 93.0°F (2024) | 70.0°F (2017) | 0.89 in (2025) |
| May 13 | 90.0°F (2008) | 62.1°F (2001) | 4.32 in (2025) |
| May 14 | 93.0°F (2019) | 66.0°F (2001) | 2.16 in (2021) |
| May 15 | 91.0°F (2017) | 70.0°F (2007) | 1.36 in (2019) |
| May 16 | 93.0°F (2024) | 66.0°F (2011) | 3.47 in (2014) |
| May 17 | 93.0°F (2024) | 68.0°F (2006) | 2.63 in (2012) |
| May 18 | 91.0°F (2024) | 66.9°F (2001) | 0.56 in (2018) |
| May 19 | 91.0°F (2024) | 70.0°F (2006) | 2.32 in (2016) |
| May 20 | 91.0°F (2024) | 69.1°F (2002) | 2.01 in (2018) |
| May 21 | 93.0°F (2024) | 70.0°F (2005) | 2.71 in (2018) |
| May 22 | 90.0°F (2008) | 71.1°F (2002) | 1.85 in (2002) |
| May 23 | 89.1°F (2015) | 62.1°F (2003) | 1.12 in (2012) |
| May 24 | 90.0°F (2017) | 64.0°F (2003) | 4.43 in (2001) |
| May 25 | 91.0°F (2017) | 71.1°F (2007) | 2.76 in (2020) |
| May 26 | 91.0°F (2005) | 66.9°F (2004) | 2.59 in (2020) |
| May 27 | 91.0°F (2024) | 71.1°F (2010) | 0.82 in (2018) |
| May 28 | 93.0°F (2017) | 71.1°F (2001) | 0.77 in (2003) |
| May 29 | 93.0°F (2017) | 70.0°F (2004) | 2.65 in (2003) |
| May 30 | 91.0°F (2017) | 63.0°F (2014) | 2.54 in (2022) |
| May 31 | 91.0°F (2017) | 63.0°F (2014) | 2.26 in (2000) |