August weather in SeaTac, WA
The average temperature in SeaTac in August is 67.4°F (57.2°F–77.6°F). Average precipitation: 0.97 inches.
August is a summer month in SeaTac, and is warmer than the annual average of 53.7°F. Daily temperatures swing about 20.4°F between overnight low and afternoon high. Expect about 5 days with precipitation. Daylight averages about 14h 4m. For travel, August is one of the best months of the year to visit.
Avg High
77.6°F
Avg Low
57.2°F
Precipitation
0.97 in
Daylight
14h 4m
August records in SeaTac
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 91.9°F (1949) | 50.0°F (1953) | 0.52 in (1964) |
| August 2 | 91.0°F (2017) | 46.0°F (1953) | 0.76 in (1996) |
| August 3 | 93.9°F (2017) | 46.0°F (1956) | 0.47 in (1996) |
| August 4 | 95.0°F (1993) | 44.1°F (1950) | 0.61 in (1962) |
| August 5 | 93.0°F (2012) | 48.9°F (1948) | 0.36 in (1948) |
| August 6 | 91.0°F (1972) | 50.0°F (1951) | 0.57 in (2004) |
| August 7 | 95.0°F (1972) | 48.0°F (1948) | 0.95 in (1976) |
| August 8 | 98.1°F (1960) | 46.9°F (1974) | 0.13 in (1953) |
| August 9 | 99.0°F (1960) | 46.9°F (1950) | 0.61 in (1957) |
| August 10 | 98.1°F (1981) | 46.0°F (1954) | 0.38 in (2019) |
| August 11 | 96.1°F (2014) | 46.0°F (1954) | 0.32 in (2009) |
| August 12 | 96.1°F (1977) | 48.9°F (1949) | 0.56 in (1965) |
| August 13 | 91.9°F (2002) | 44.1°F (1955) | 0.85 in (2014) |
| August 14 | 95.0°F (2010) | 44.1°F (1955) | 1.60 in (1968) |
| August 15 | 96.1°F (2010) | 46.9°F (1955) | 1.20 in (1950) |
| August 16 | 98.1°F (1967) | 50.0°F (1986) | 0.41 in (1995) |
| August 17 | 96.1°F (1977) | 45.0°F (1951) | 0.93 in (1995) |
| August 18 | 88.0°F (1991) | 46.9°F (1951) | 1.63 in (1975) |
| August 19 | 95.0°F (2016) | 48.0°F (1951) | 0.88 in (1965) |
| August 20 | 91.0°F (2016) | 46.9°F (1952) | 0.70 in (2008) |
| August 21 | 91.0°F (2018) | 46.0°F (1973) | 0.70 in (1989) |
| August 22 | 89.1°F (2018) | 45.0°F (1960) | 1.41 in (2001) |
| August 23 | 91.0°F (1988) | 46.0°F (1955) | 1.49 in (1977) |
| August 24 | 90.0°F (2025) | 45.0°F (1951) | 1.00 in (2004) |
| August 25 | 91.0°F (2016) | 45.0°F (1954) | 0.59 in (1968) |
| August 26 | 91.9°F (2016) | 46.0°F (1957) | 0.67 in (1977) |
| August 27 | 88.0°F (1986) | 44.1°F (1952) | 0.76 in (1951) |
| August 28 | 95.0°F (1967) | 46.0°F (1952) | 0.47 in (1975) |
| August 29 | 91.0°F (1974) | 44.1°F (1951) | 1.28 in (2015) |
| August 30 | 90.0°F (2022) | 45.0°F (1950) | 0.40 in (2015) |
| August 31 | 91.9°F (1987) | 46.0°F (1950) | 0.56 in (1961) |