May weather in Diamond Bar, CA
The average temperature in Diamond Bar in May is 66.2°F (54.0°F–78.4°F). Average precipitation: 0.22 inches.
May is a spring month in Diamond Bar, and is warmer than the annual average of 65.1°F. Daily temperatures swing about 24.4°F between overnight low and afternoon high. Expect about 1 days with precipitation. Daylight averages about 13h 46m. For travel, May is one of the best months of the year to visit.
Avg High
78.4°F
Avg Low
54.0°F
Precipitation
0.22 in
Daylight
13h 46m
May records in Diamond Bar
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| May 1 | 99.0°F (1947) | 30.9°F (1915) | 1.08 in (1941) |
| May 2 | 100.9°F (2004) | 33.1°F (1913) | 0.70 in (1930) |
| May 3 | 102.9°F (2004) | 35.1°F (1933) | 0.22 in (1930) |
| May 4 | 97.0°F (1928) | 34.0°F (1950) | 0.85 in (1930) |
| May 5 | 100.0°F (1928) | 32.0°F (1920) | 1.27 in (1900) |
| May 6 | 98.1°F (1990) | 36.0°F (1920) | 0.84 in (1921) |
| May 7 | 98.1°F (1923) | 36.0°F (1933) | 0.86 in (1955) |
| May 8 | 102.9°F (1923) | 34.0°F (1950) | 1.34 in (1977) |
| May 9 | 102.9°F (1923) | 36.0°F (1950) | 0.75 in (1928) |
| May 10 | 102.9°F (1934) | 33.1°F (1922) | 0.90 in (1977) |
| May 11 | 99.0°F (1934) | 36.0°F (1918) | 0.38 in (1957) |
| May 12 | 97.0°F (1927) | 37.9°F (1920) | 0.05 in (1958) |
| May 13 | 104.0°F (1927) | 39.0°F (1930) | 0.03 in (1923) |
| May 14 | 100.9°F (1927) | 37.9°F (1930) | 0.21 in (1925) |
| May 15 | 96.1°F (1900) | 37.9°F (1955) | 1.12 in (1898) |
| May 16 | 100.9°F (1956) | 37.0°F (1943) | 0.16 in (1930) |
| May 17 | 100.9°F (2008) | 37.9°F (1943) | 0.08 in (1949) |
| May 18 | 102.0°F (2008) | 37.9°F (1945) | 0.19 in (2011) |
| May 19 | 100.0°F (1942) | 39.0°F (1933) | 0.54 in (1957) |
| May 20 | 105.1°F (1942) | 35.1°F (1948) | 0.29 in (1949) |
| May 21 | 98.1°F (2003) | 34.0°F (1948) | 0.73 in (1921) |
| May 22 | 98.1°F (2005) | 36.0°F (1927) | 1.27 in (1921) |
| May 23 | 99.0°F (1949) | 39.0°F (1939) | 0.57 in (1921) |
| May 24 | 97.0°F (1896) | 37.9°F (1916) | 0.42 in (1977) |
| May 25 | 105.1°F (1896) | 35.1°F (1916) | 0.30 in (1931) |
| May 26 | 100.0°F (1968) | 36.0°F (1917) | 0.12 in (1931) |
| May 27 | 100.0°F (1915) | 37.9°F (1917) | 0.86 in (1906) |
| May 28 | 100.9°F (1984) | 37.9°F (1917) | 1.07 in (1990) |
| May 29 | 106.0°F (1984) | 39.0°F (1953) | 0.90 in (2004) |
| May 30 | 100.9°F (1978) | 37.9°F (1929) | 0.00 in (1895) |
| May 31 | 96.1°F (1938) | 39.9°F (1949) | 0.10 in (1991) |