May weather in Union, IA
The average temperature in Union in May is 59.2°F (48.0°F–70.4°F). Average precipitation: 5.21 inches. Average snowfall is 0.4 inches.
May is a spring month in Union, and is warmer than the annual average of 46.9°F. Daily temperatures swing about 22.4°F between overnight low and afternoon high. Expect about 14 days with precipitation. Daylight averages about 14h 24m. For travel, May is a wet month.
Avg High
70.4°F
Avg Low
48.0°F
Precipitation
5.21 in
Snow
0.4 in
May records in Union
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| May 1 | 90.0°F (2007) | 27.0°F (1961) | 1.88 in (1997) |
| May 2 | 90.0°F (2021) | 28.0°F (1970) | 0.87 in (1993) |
| May 3 | 89.1°F (1968) | 27.0°F (2005) | 1.80 in (1979) |
| May 4 | 86.0°F (1959) | 28.9°F (2005) | 1.11 in (2018) |
| May 5 | 90.0°F (1962) | 28.9°F (1958) | 1.70 in (2003) |
| May 6 | 87.1°F (1980) | 28.0°F (1989) | 2.12 in (1960) |
| May 7 | 86.0°F (2016) | 28.0°F (1989) | 3.10 in (2008) |
| May 8 | 90.0°F (1963) | 30.0°F (1989) | 1.99 in (1950) |
| May 9 | 86.0°F (1963) | 27.0°F (2020) | 2.48 in (1990) |
| May 10 | 90.0°F (2022) | 28.0°F (1966) | 1.00 in (1957) |
| May 11 | 93.9°F (2011) | 33.1°F (1981) | 1.33 in (2001) |
| May 12 | 91.9°F (2022) | 30.9°F (2013) | 2.00 in (1982) |
| May 13 | 93.9°F (2022) | 30.9°F (1997) | 1.87 in (2010) |
| May 14 | 89.1°F (1991) | 30.9°F (2016) | 1.18 in (1970) |
| May 15 | 95.0°F (2013) | 32.0°F (1997) | 0.79 in (2015) |
| May 16 | 91.0°F (2001) | 34.0°F (1997) | 1.54 in (1991) |
| May 17 | 90.0°F (2019) | 35.1°F (2009) | 1.23 in (2020) |
| May 18 | 91.9°F (1987) | 37.0°F (1973) | 1.72 in (1971) |
| May 19 | 91.0°F (1967) | 36.0°F (1965) | 3.03 in (1983) |
| May 20 | 90.0°F (1975) | 37.0°F (1967) | 1.14 in (2013) |
| May 21 | 90.0°F (1964) | 37.0°F (2002) | 1.70 in (1982) |
| May 22 | 91.0°F (1972) | 30.0°F (1963) | 2.25 in (1983) |
| May 23 | 91.0°F (1970) | 28.0°F (1963) | 3.23 in (1966) |
| May 24 | 91.0°F (1972) | 37.0°F (1963) | 3.10 in (2007) |
| May 25 | 91.0°F (2010) | 39.9°F (1992) | 1.48 in (2022) |
| May 26 | 93.9°F (1967) | 34.0°F (1961) | 2.00 in (2013) |
| May 27 | 95.0°F (2018) | 36.0°F (1961) | 3.18 in (2013) |
| May 28 | 98.1°F (2018) | 35.1°F (1965) | 1.90 in (1954) |
| May 29 | 97.0°F (2018) | 33.1°F (1965) | 2.54 in (1976) |
| May 30 | 93.9°F (2018) | 37.9°F (1984) | 2.84 in (2008) |
| May 31 | 91.0°F (1988) | 37.0°F (1972) | 2.07 in (1951) |