May weather in SeaTac, WA
The average temperature in SeaTac in May is 57.5°F (48.7°F–66.3°F). Average precipitation: 1.88 inches.
May is a spring month in SeaTac, and is warmer than the annual average of 53.7°F. Daily temperatures swing about 17.6°F between overnight low and afternoon high. Expect about 11 days with precipitation. Daylight averages about 14h 54m. For travel, May is a comfortable month to visit.
Avg High
66.3°F
Avg Low
48.7°F
Precipitation
1.88 in
Daylight
14h 54m
May records in SeaTac
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| May 1 | 84.9°F (2014) | 28.0°F (1954) | 0.81 in (1949) |
| May 2 | 87.1°F (2016) | 33.1°F (1952) | 0.47 in (1975) |
| May 3 | 77.0°F (1992) | 35.1°F (1950) | 1.31 in (2014) |
| May 4 | 84.9°F (1992) | 33.1°F (1962) | 0.66 in (1965) |
| May 5 | 86.0°F (1953) | 36.0°F (1949) | 0.70 in (2023) |
| May 6 | 87.1°F (2013) | 36.0°F (1965) | 0.89 in (2009) |
| May 7 | 82.0°F (2016) | 33.1°F (1962) | 0.66 in (1983) |
| May 8 | 84.0°F (1969) | 36.0°F (1999) | 0.54 in (2014) |
| May 9 | 86.0°F (2020) | 37.9°F (1955) | 0.74 in (2000) |
| May 10 | 87.1°F (2020) | 37.9°F (1953) | 0.61 in (2000) |
| May 11 | 87.1°F (1971) | 35.1°F (1953) | 0.47 in (1954) |
| May 12 | 82.0°F (2023) | 37.9°F (1964) | 0.71 in (1996) |
| May 13 | 86.0°F (2023) | 37.0°F (1956) | 0.44 in (2009) |
| May 14 | 89.1°F (2023) | 36.0°F (1964) | 0.97 in (2011) |
| May 15 | 88.0°F (2023) | 37.9°F (1964) | 0.81 in (2011) |
| May 16 | 84.0°F (1985) | 39.9°F (2003) | 0.64 in (1988) |
| May 17 | 90.0°F (2008) | 39.0°F (1966) | 0.72 in (1989) |
| May 18 | 89.1°F (1958) | 37.0°F (1950) | 0.72 in (2005) |
| May 19 | 88.0°F (1963) | 37.9°F (1975) | 0.70 in (1968) |
| May 20 | 91.9°F (1963) | 39.9°F (1960) | 0.56 in (2007) |
| May 21 | 93.0°F (1963) | 39.0°F (1960) | 0.66 in (2024) |
| May 22 | 86.0°F (1969) | 37.0°F (1960) | 0.67 in (1984) |
| May 23 | 90.0°F (1969) | 37.0°F (1950) | 0.70 in (1962) |
| May 24 | 89.1°F (1992) | 37.0°F (1950) | 0.65 in (1998) |
| May 25 | 84.0°F (2001) | 37.0°F (1964) | 0.41 in (2011) |
| May 26 | 89.1°F (2005) | 39.9°F (1952) | 0.61 in (1954) |
| May 27 | 89.1°F (2005) | 37.0°F (1966) | 0.83 in (1948) |
| May 28 | 91.9°F (1983) | 37.9°F (1954) | 0.88 in (1948) |
| May 29 | 84.9°F (1973) | 35.1°F (1951) | 1.83 in (1969) |
| May 30 | 87.1°F (1956) | 36.0°F (1951) | 1.14 in (2020) |
| May 31 | 90.0°F (1964) | 35.1°F (1953) | 0.97 in (1977) |