Below are record temperatures in Dallas for every day in August. Notice that only two of these occurred during the past 10 years.
Aug 01 - 105° (1985)
Aug 02 - 104° (1985)
Aug 03 - 103° (1951)
Aug 04 - 105° (1951)
Aug 05 - 109° (1956)
Aug 06 - 109° (2003)
Aug 07 - 107° (1953)
Aug 08 - 108° (1953)
Aug 09 - 103° (1999)
Aug 10 - 105° (1999)
Aug 11 - 107° (1953)
Aug 12 - 105° (1983)
Aug 13 - 105° (1969)
Aug 14 - 106° (1956)
Aug 15 - 106° (1951)
Aug 16 - 107° (1956)
Aug 17 - 107° (1951)
Aug 18 - 105° (1951)
Aug 19 - 108° (1984)
Aug 20 - 107° (1948)
Aug 21 - 107° (1980)
Aug 22 - 105° (1980)
Aug 23 - 106° (1988)
Aug 24 - 103° (2006)
Aug 25 - 104° (1952)
Aug 26 - 105° (1999)
Aug 27 - 103° (1995)
Aug 28 - 106° (1995)
Aug 29 - 106° (1984)
Aug 30 - 107° (1954)
Aug 31 - 106° (2000)
Source:
Intellicast - Dallas Historic Weather Averages in Texas (75235)