May weather in Alton, MO
The average temperature in Alton in May is 64.5°F (53.1°F–75.8°F). Average precipitation: 5.57 inches.
May is a spring month in Alton, and is warmer than the annual average of 55.7°F. Daily temperatures swing about 22.7°F between overnight low and afternoon high. Expect about 10 days with precipitation. Daylight averages about 13h 57m. For travel, May is a wet month.
Avg High
75.8°F
Avg Low
53.1°F
Precipitation
5.57 in
Daylight
13h 57m
May records in Alton
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| May 1 | 88.0°F (2007) | 30.0°F (1963) | 2.06 in (2011) |
| May 2 | 88.0°F (1968) | 32.0°F (1978) | 3.19 in (2011) |
| May 3 | 84.0°F (2001) | 30.0°F (1967) | 2.21 in (1958) |
| May 4 | 88.0°F (1965) | 28.0°F (1976) | 1.61 in (2021) |
| May 5 | 88.0°F (1969) | 30.0°F (2005) | 2.98 in (1958) |
| May 6 | 89.1°F (1966) | 36.0°F (1968) | 1.45 in (1960) |
| May 7 | 90.0°F (1966) | 39.9°F (1976) | 3.60 in (1961) |
| May 8 | 90.0°F (1966) | 35.1°F (1976) | 2.10 in (2002) |
| May 9 | 86.0°F (1966) | 30.9°F (1976) | 3.45 in (2009) |
| May 10 | 88.0°F (1973) | 33.1°F (1966) | 2.50 in (1950) |
| May 11 | 91.0°F (1967) | 34.0°F (1969) | 1.93 in (1968) |
| May 12 | 90.0°F (2005) | 37.9°F (1977) | 4.60 in (1950) |
| May 13 | 89.1°F (1984) | 35.1°F (2008) | 2.55 in (1967) |
| May 14 | 89.1°F (1998) | 35.1°F (2008) | 2.12 in (2011) |
| May 15 | 87.1°F (1963) | 34.0°F (1973) | 2.62 in (1956) |
| May 16 | 89.1°F (2001) | 34.0°F (1997) | 0.90 in (1953) |
| May 17 | 91.0°F (2001) | 35.1°F (1997) | 2.36 in (2002) |
| May 18 | 89.1°F (2001) | 35.1°F (1968) | 1.65 in (1952) |
| May 19 | 90.0°F (1974) | 36.0°F (1976) | 2.36 in (1960) |
| May 20 | 90.0°F (1964) | 39.0°F (1968) | 1.76 in (2010) |
| May 21 | 90.0°F (1972) | 37.0°F (1981) | 3.03 in (1979) |
| May 22 | 91.9°F (1998) | 37.0°F (1981) | 2.98 in (1974) |
| May 23 | 89.1°F (1970) | 34.0°F (1963) | 3.26 in (1957) |
| May 24 | 93.9°F (2000) | 39.9°F (1979) | 1.13 in (1971) |
| May 25 | 91.0°F (2000) | 39.0°F (1979) | 1.48 in (1964) |
| May 26 | 93.9°F (2012) | 44.1°F (2003) | 2.03 in (1963) |
| May 27 | 95.0°F (2012) | 44.1°F (1999) | 4.57 in (1973) |
| May 28 | 93.9°F (2012) | 39.9°F (1984) | 1.65 in (2017) |
| May 29 | 93.0°F (2012) | 35.1°F (1984) | 2.15 in (1950) |
| May 30 | 93.0°F (2012) | 36.0°F (1984) | 1.10 in (2019) |
| May 31 | 89.1°F (1969) | 42.1°F (1971) | 1.87 in (2001) |