The following table lists the daily mean and record temperatures (°F) at Brookhaven National Laboratory for each day of the month. The period covered is from 1949 to 2006.
| Maximum | Minimum | ||||||
| Day | Mean | Average | High | Year | Average | Low | Year |
| 1 | 72.8 | 83.2 | 96.5 | 2006 | 62.4 | 46.0 | 1964 |
| 2 | 72.8 | 82.9 | 99.5 | 1975 | 62.7 | 49.0 | 1956 |
| 3 | 72.9 | 82.8 | 99.5 | 2006 | 63.1 | 42.0 | 1959 |
| 4 | 72.8 | 82.5 | 93.0 | 2005 | 63.0 | 42.0 | 1964 |
| 5 | 72.1 | 81.9 | 96.0 | 1955 | 62.4 | 45.0 | 1972 |
| 6 | 70.6 | 80.9 | 94.0 | 1955 | 60.2 | 39.0 | 1972 |
| 7 | 71.0 | 81.5 | 95.0 | 2001 | 60.5 | 43.0 | 1951 |
| 8 | 71.9 | 82.3 | 98.5 | 2001 | 61.5 | 44.0 | 1950 |
| 9 | 72.0 | 82.0 | 99.5 | 2001 | 62.0 | 44.0 | 1955 |
| 10 | 71.9 | 81.6 | 96.0 | 1949 | 62.2 | 39.0 | 1964 |
| 11 | 71.6 | 80.7 | 99.0 | 1949 | 62.5 | 41.0 | 1974 |
| 12 | 70.6 | 80.3 | 92.5 | 2005 | 61.0 | 42.0 | 1968 |
| 13 | 70.4 | 80.0 | 93.5 | 2002 | 60.9 | 43.0 | 1971 |
| 14 | 70.9 | 81.3 | 92.0 | 1974 | 60.6 | 44.0 | 1971 |
| 15 | 70.9 | 80.7 | 91.0 | 1985 | 61.1 | 43.0 | 1972 |
| 16 | 70.6 | 81.0 | 91.5 | 1997 | 60.2 | 40.0 | 1972 |
| 17 | 71.0 | 80.7 | 92.5 | 2002 | 61.3 | 46.0 | 1979 |
| 18 | 69.3 | 79.9 | 93.5 | 2002 | 58.7 | 42.5 | 1961 |
| 19 | 68.8 | 79.7 | 94.0 | 2002 | 57.9 | 42.0 | 1953 |
| 20 | 69.0 | 79.9 | 95.0 | 1983 | 58.2 | 44.5 | 1964 |
| 21 | 68.3 | 79.3 | 94.0 | 1995 | 57.3 | 41.5 | 1977 |
| 22 | 68.5 | 79.7 | 91.0 | 1976 | 57.3 | 40.0 | 1982 |
| 23 | 67.6 | 79.0 | 88.5 | 1989 | 56.2 | 39.0 | 1957 |
| 24 | 67.7 | 78.8 | 90.0 | 1995 | 56.5 | 37.0 | 1957 |
| 25 | 67.6 | 78.7 | 92.0 | 1993 | 56.5 | 38.5 | 1971 |
| 26 | 68.3 | 79.9 | 91.0 | 1993 | 56.7 | 40.0 | 1960 |
| 27 | 71.1 | 81.2 | 93.0 | 1993 | 60.9 | 46.0 | 1964 |
| 28 | 70.9 | 80.5 | 96.0 | 1973 | 61.4 | 41.0 | 1986 |
| 29 | 70.6 | 80.4 | 96.0 | 1953 | 60.7 | 39.0 | 1986 |
| 30 | 69.9 | 79.9 | 97.0 | 1973 | 59.9 | 38.0 | 1986 |
| 31 | 69.3 | 9.1 | 99.0 | 1953 | 59.6 | 37.0 | 1965 |
| Mean | 70.4 | 80.7 | 94.5 | 60.2 | 41.9 | ||