no - it's the mean maximum temperature for the entire month. Which means - in the last 30 years, on average, the maximum temperature observed at DCA was 67F. In July, DCA's mean maximum monthly temperature is 98F - which means that's on average as hot as it gets here in July. You can see here: https://en.wikipedia.org/wiki/Washington,_D.C.#Climate
The row in question in the climate table is "Mean maximum"