May weather in Johnston, SC
The average temperature in Johnston in May is 70.3°F (57.3°F–83.4°F). Average precipitation: 3.21 inches.
May is a spring month in Johnston, and is warmer than the annual average of 62.7°F. Daily temperatures swing about 26.1°F between overnight low and afternoon high. Expect about 8 days with precipitation. Daylight averages about 13h 45m. For travel, May is a comfortable month to visit.
Avg High
83.4°F
Avg Low
57.3°F
Precipitation
3.21 in
Daylight
13h 45m
May records in Johnston
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| May 1 | 93.9°F (2012) | 37.9°F (1996) | 0.75 in (1999) |
| May 2 | 93.0°F (2007) | 39.0°F (1980) | 1.40 in (1975) |
| May 3 | 93.9°F (2010) | 37.9°F (2005) | 2.65 in (1964) |
| May 4 | 93.0°F (2007) | 34.0°F (2004) | 2.22 in (1997) |
| May 5 | 91.0°F (1996) | 34.0°F (2004) | 1.62 in (1990) |
| May 6 | 95.0°F (2012) | 37.9°F (1997) | 2.14 in (1991) |
| May 7 | 93.0°F (1977) | 37.0°F (2007) | 1.02 in (2003) |
| May 8 | 93.0°F (1959) | 36.0°F (1989) | 2.92 in (1998) |
| May 9 | 93.9°F (2002) | 39.9°F (1989) | 1.52 in (1978) |
| May 10 | 93.9°F (2002) | 41.0°F (1977) | 2.87 in (1962) |
| May 11 | 93.0°F (2002) | 37.9°F (1977) | 1.64 in (2008) |
| May 12 | 93.0°F (1963) | 42.1°F (1977) | 1.32 in (2021) |
| May 13 | 97.0°F (2000) | 41.0°F (1960) | 1.54 in (2004) |
| May 14 | 99.0°F (2000) | 42.1°F (1997) | 1.23 in (1972) |
| May 15 | 91.9°F (1982) | 39.9°F (2021) | 0.96 in (1976) |
| May 16 | 96.1°F (1995) | 41.0°F (2002) | 1.71 in (2014) |
| May 17 | 98.1°F (2001) | 43.0°F (2014) | 2.20 in (1991) |
| May 18 | 98.1°F (1995) | 42.1°F (1979) | 2.02 in (2020) |
| May 19 | 97.0°F (1996) | 41.0°F (1976) | 1.36 in (2023) |
| May 20 | 98.1°F (1996) | 37.9°F (2002) | 1.52 in (1974) |
| May 21 | 97.0°F (1996) | 37.9°F (2002) | 1.08 in (1972) |
| May 22 | 97.0°F (1996) | 39.9°F (2002) | 4.65 in (2003) |
| May 23 | 95.0°F (2004) | 39.9°F (2002) | 3.01 in (1967) |
| May 24 | 95.0°F (1998) | 39.0°F (2002) | 2.95 in (1976) |
| May 25 | 97.0°F (1996) | 39.9°F (2005) | 1.12 in (2017) |
| May 26 | 100.0°F (2000) | 39.9°F (1979) | 1.66 in (1970) |
| May 27 | 100.0°F (2019) | 41.0°F (1961) | 2.30 in (2015) |
| May 28 | 100.0°F (2000) | 41.0°F (1997) | 2.64 in (1986) |
| May 29 | 100.0°F (2019) | 43.0°F (1961) | 2.52 in (1963) |
| May 30 | 99.0°F (2019) | 48.9°F (1971) | 1.39 in (1979) |
| May 31 | 99.0°F (2019) | 44.1°F (1984) | 1.50 in (2005) |