Agree with parts of some responses. Absolutely should continue to lift in-season! It is all about decreasing frequency/volume and maintaining intensity. One of the biggest mistakes I see made with in-season programs is that coaches go with lighter weights...so maybe 3 sets of squats x 8 reps @ 50% (or lower) of max. That makes no sense. Sure, they are still moving around in the weightroom but they are in a detraining mode which will have a negative effect on performance. IMO...go with fewer training sessions, fewer exercises, fewer sets/reps, and keep the intensity up. Going back to squat exercise, instead of 3 x 8, go 3 x 3 or 3 x 2 (after properly warmed up) @ 90-95% of 1RM. There will be less fatigue (24 reps v 6-9 reps in the example provided). Your players will stay strong and in some cases get stronger!
Sorry...back to the original question. I am not a big fan of lifting that close to game time. I get that they are high school kids and recover quickly but finishing up 2 1/2 hours before being back on the field is not...IMO...the best way to approach in-season training. If they were coming in before school for a short session followed by an opportunity to fuel up shortly after...definitely doable IMO.
Have to be careful with the...when I was in school we lifted on game days. There is a lot that has changed in regards to performance training in just a short period of time.
Last recommendation...read up on Eric Cressey's recommendations. Great resource.