It has been a long time since I was stationed in Montgomery, AL. I was assigned at Gunter Annex which is across town from Maxwell. Summertime can be very warm, upper 90s, with very high humidity. Again in the upper 90s. There tends to be a lot of thunder storms during the summer there and they can be very impressive. If you get any free time, DO NOT be tempted to swim in the river. Lots of gators. A friend tried it a couple of times until he realized the floating logs weren't logs.
I know a lot of people down there that tend to limit their outside activities during the summer. As long as you drink lots of water you should be okay. And I do mean a lot. You should get safety briefings about those kind of things when you arrive there. If you have a tendency to burn in the sun use a lot of sunblock. Use a lot even if you don't burn easily. You do not want to spend time recovering from sun burns.
Most of all, enjoy the time you have there. Within the limits of your schedule anyway! If you play and have the chance, there are several very good golf courses in Montgomery including the 2 that are on Maxwell. There is also the Robert Trent Jones Golf Trail which includes some really great courses. One of them is in Prattville which is about 10 miles north of Maxwell.
Drink lots of water.