May weather in St. Marys, PA
The average temperature in St. Marys in May is 54.7°F (41.9°F–67.4°F). Average precipitation: 4.32 inches. Average snowfall is 0.2 inches.
May is a spring month in St. Marys, and is warmer than the annual average of 45.1°F. Daily temperatures swing about 25.5°F between overnight low and afternoon high. Expect about 15 days with precipitation. Daylight averages about 14h 20m. For travel, May is a comfortable month to visit.
Avg High
67.4°F
Avg Low
41.9°F
Precipitation
4.32 in
Snow
0.2 in
May records in St. Marys
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| May 1 | 80.1°F (2010) | 27.0°F (2008) | 0.98 in (1996) |
| May 2 | 82.9°F (2010) | 30.9°F (2012) | 1.25 in (1989) |
| May 3 | 82.9°F (2018) | 30.9°F (2023) | 0.89 in (2012) |
| May 4 | 84.0°F (2024) | 27.0°F (2004) | 1.24 in (2011) |
| May 5 | 80.1°F (2012) | 27.0°F (2005) | 0.85 in (1990) |
| May 6 | 78.1°F (2010) | 28.0°F (2020) | 1.09 in (2017) |
| May 7 | 75.9°F (2004) | 25.0°F (2020) | 1.13 in (1956) |
| May 8 | 81.0°F (2015) | 25.0°F (2020) | 1.36 in (2012) |
| May 9 | 86.0°F (2015) | 19.9°F (2020) | 1.12 in (1969) |
| May 10 | 86.0°F (2015) | 19.9°F (2020) | 1.30 in (2021) |
| May 11 | 87.1°F (2015) | 19.9°F (2020) | 1.39 in (1979) |
| May 12 | 84.0°F (2015) | 30.0°F (2009) | 1.92 in (1981) |
| May 13 | 84.0°F (2022) | 25.0°F (2020) | 1.95 in (2002) |
| May 14 | 86.0°F (2014) | 25.0°F (2013) | 1.37 in (1956) |
| May 15 | 82.0°F (2022) | 28.0°F (2013) | 0.92 in (1957) |
| May 16 | 84.0°F (2007) | 28.0°F (2016) | 1.36 in (2014) |
| May 17 | 80.1°F (2013) | 28.9°F (2005) | 1.67 in (1970) |
| May 18 | 84.0°F (2017) | 27.0°F (2009) | 0.94 in (2002) |
| May 19 | 82.9°F (2017) | 25.0°F (2023) | 2.20 in (2000) |
| May 20 | 84.9°F (2019) | 32.0°F (2008) | 1.29 in (1949) |
| May 21 | 84.0°F (2024) | 33.1°F (2008) | 1.94 in (2014) |
| May 22 | 86.0°F (2013) | 36.0°F (2015) | 1.16 in (1944) |
| May 23 | 84.9°F (2013) | 27.0°F (2015) | 2.67 in (1953) |
| May 24 | 82.0°F (2004) | 30.0°F (2015) | 1.14 in (1962) |
| May 25 | 82.9°F (2007) | 32.0°F (2013) | 1.33 in (1975) |
| May 26 | 82.9°F (2012) | 28.9°F (2013) | 2.09 in (1943) |
| May 27 | 86.0°F (2010) | 30.9°F (2013) | 1.43 in (1946) |
| May 28 | 84.9°F (2010) | 33.1°F (2008) | 1.81 in (1985) |
| May 29 | 87.1°F (2018) | 34.0°F (2008) | 1.98 in (2013) |
| May 30 | 89.1°F (2006) | 34.0°F (2008) | 1.00 in (1983) |
| May 31 | 89.1°F (2006) | 34.0°F (2024) | 1.70 in (1953) |