Yes, it should be better than October. It will be Halloweeentime so it will be busier than say the last week of August but should not be to the level of October. I am planning to go somewhere in that time period this year too. After Halloween starts but as near the beginning-ish of the season as possible while avoiding the very first weekend of Halloweentime. There will probably be Oggie Boogie Bash parties some of the nights so DCA will close early those days so just plan to plan your days around that or maybe go to a party one night. My kids will be almost 2 and almost 4 in September so I am going to wait a few more years to take them because they don't stay up late well yet. It is likely to still be hot at that point so be prepared for that. We have been know to get heatwaves all the way to mid October that put temps up to high 90's or 100s but more likely it will be in the mid to high 80s, possibly low 90s at the peak of the day.