May weather in Great Falls, MT
The average temperature in Great Falls in May is 54.4°F (41.9°F–67.0°F). Average precipitation: 2.66 inches.
May is a spring month in Great Falls, and is warmer than the annual average of 47°F. Daily temperatures swing about 25.1°F between overnight low and afternoon high. Expect about 11 days with precipitation. Daylight averages about 14h 54m. For travel, May is a comfortable month to visit.
Avg High
67.0°F
Avg Low
41.9°F
Precipitation
2.66 in
Daylight
14h 54m
May records in Great Falls
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| May 1 | 82.9°F (1897) | 18.0°F (1954) | 0.57 in (1920) |
| May 2 | 81.0°F (1918) | 12.0°F (1954) | 0.45 in (1902) |
| May 3 | 86.0°F (1897) | 21.0°F (1899) | 0.75 in (1901) |
| May 4 | 87.1°F (1897) | 28.0°F (1919) | 0.90 in (1917) |
| May 5 | 89.1°F (2017) | 26.1°F (1917) | 1.15 in (2025) |
| May 6 | 88.0°F (1928) | 23.0°F (1919) | 1.26 in (2017) |
| May 7 | 88.0°F (1953) | 24.1°F (1892) | 0.38 in (1921) |
| May 8 | 84.9°F (1928) | 24.1°F (1894) | 0.60 in (1918) |
| May 9 | 81.0°F (1900) | 28.9°F (1892) | 0.64 in (2011) |
| May 10 | 88.0°F (1936) | 21.9°F (1894) | 0.97 in (1914) |
| May 11 | 86.0°F (2025) | 26.1°F (1953) | 1.28 in (2018) |
| May 12 | 87.1°F (1932) | 26.1°F (1953) | 1.40 in (1900) |
| May 13 | 89.1°F (1931) | 26.1°F (1953) | 0.43 in (2017) |
| May 14 | 95.0°F (1936) | 28.9°F (1916) | 0.38 in (1923) |
| May 15 | 93.0°F (1897) | 28.0°F (1929) | 2.75 in (1902) |
| May 16 | 91.0°F (1897) | 32.0°F (1909) | 1.71 in (1894) |
| May 17 | 89.1°F (2006) | 27.0°F (1903) | 0.78 in (2017) |
| May 18 | 91.0°F (2006) | 27.0°F (1903) | 0.64 in (2018) |
| May 19 | 93.9°F (1919) | 30.0°F (1903) | 0.55 in (1903) |
| May 20 | 93.9°F (1897) | 28.0°F (1903) | 0.66 in (1902) |
| May 21 | 89.1°F (1928) | 30.0°F (2009) | 1.13 in (1927) |
| May 22 | 97.0°F (1919) | 32.0°F (2009) | 0.53 in (2008) |
| May 23 | 88.0°F (1919) | 30.9°F (1930) | 0.98 in (1914) |
| May 24 | 90.0°F (1919) | 30.9°F (1904) | 1.51 in (2011) |
| May 25 | 93.9°F (1928) | 30.9°F (1918) | 2.83 in (1953) |
| May 26 | 93.9°F (1936) | 30.0°F (1920) | 1.05 in (1922) |
| May 27 | 95.0°F (1936) | 28.0°F (1918) | 1.04 in (2006) |
| May 28 | 100.0°F (1919) | 28.0°F (1918) | 1.38 in (1898) |
| May 29 | 95.0°F (1936) | 30.9°F (1895) | 1.99 in (1953) |
| May 30 | 93.0°F (1933) | 30.9°F (1917) | 1.14 in (2011) |
| May 31 | 90.0°F (1936) | 28.0°F (1917) | 0.83 in (1897) |