July weather in St. Marys, IA
The average temperature in St. Marys in July is 74.7°F (64.0°F–85.5°F). Average precipitation: 4.32 inches.
July is a summer month in St. Marys, and is warmer than the annual average of 49.9°F. Daily temperatures swing about 21.5°F between overnight low and afternoon high. Expect about 8 days with precipitation. Daylight averages about 14h 42m. For travel, July is a comfortable month to visit.
Avg High
85.5°F
Avg Low
64.0°F
Precipitation
4.32 in
Daylight
14h 42m
July records in St. Marys
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| July 1 | 102.9°F (1925) | 48.9°F (1918) | 1.42 in (1941) |
| July 2 | 102.9°F (1911) | 46.9°F (1968) | 2.25 in (1958) |
| July 3 | 104.0°F (1911) | 45.0°F (1968) | 3.05 in (2024) |
| July 4 | 106.0°F (1936) | 44.1°F (1967) | 2.35 in (1981) |
| July 5 | 105.1°F (1911) | 42.1°F (1972) | 2.06 in (1920) |
| July 6 | 102.9°F (1954) | 44.1°F (1972) | 4.16 in (1982) |
| July 7 | 100.0°F (2012) | 46.9°F (1984) | 2.05 in (1899) |
| July 8 | 99.0°F (1989) | 52.0°F (1952) | 4.11 in (2008) |
| July 9 | 102.9°F (1930) | 51.1°F (1953) | 3.41 in (1902) |
| July 10 | 104.0°F (1930) | 46.9°F (1996) | 1.92 in (1987) |
| July 11 | 102.9°F (1936) | 50.0°F (1945) | 1.96 in (2009) |
| July 12 | 106.0°F (1939) | 51.1°F (1897) | 1.88 in (2016) |
| July 13 | 107.1°F (1936) | 46.0°F (1975) | 2.83 in (1952) |
| July 14 | 106.0°F (1936) | 45.0°F (1967) | 2.69 in (1942) |
| July 15 | 108.0°F (1936) | 46.0°F (1930) | 2.82 in (1984) |
| July 16 | 102.0°F (1936) | 46.9°F (1896) | 1.83 in (1900) |
| July 17 | 104.0°F (1936) | 50.0°F (1911) | 1.58 in (1969) |
| July 18 | 107.1°F (1934) | 54.0°F (1914) | 2.14 in (2008) |
| July 19 | 111.9°F (1934) | 51.1°F (1947) | 3.19 in (1904) |
| July 20 | 109.9°F (1934) | 52.0°F (1970) | 3.27 in (2016) |
| July 21 | 109.0°F (1934) | 46.9°F (1970) | 1.82 in (1976) |
| July 22 | 109.0°F (1901) | 51.1°F (1896) | 0.96 in (1935) |
| July 23 | 104.0°F (1934) | 46.9°F (1896) | 2.00 in (1896) |
| July 24 | 108.0°F (1934) | 46.9°F (1896) | 2.76 in (2010) |
| July 25 | 111.0°F (1936) | 46.0°F (1896) | 1.27 in (1948) |
| July 26 | 107.1°F (1936) | 51.1°F (1984) | 1.96 in (2006) |
| July 27 | 108.0°F (1930) | 45.0°F (1971) | 2.70 in (1915) |
| July 28 | 104.0°F (1931) | 46.9°F (2013) | 3.21 in (2008) |
| July 29 | 102.0°F (1913) | 46.9°F (1981) | 5.61 in (2015) |
| July 30 | 106.0°F (1955) | 39.9°F (1984) | 1.11 in (1940) |
| July 31 | 104.0°F (1955) | 39.9°F (1971) | 2.41 in (2024) |