I love September - apart from the annual arachnid invasion of my house.
Here's something different for you to try... relaxing, educational, primal and just a little bit hippy.
Download one of these charts, sharpen your old penknife (or get one of these), buy the poor man's BushBuddy for a tenner and go and spend an hour or two in your local woods. Not the horrible coniferised F.E. forests, but a real woodland.
Spend some time getting away from the dog walking paths, find a nice quite spot, sit on your rucksack, make yourself a brew or two with your little woodburner (maybe even some lunch), whittle a stick and just chill.
Sit there long enough (and quiet enough) and it's a totally different outdoor experience to the hills we know and love. Wildlife comes and finds you. If you are brave enough and The Blair Witch Project is a distant memory, try camping in the woods.
Use the chart to learn some trees on the way.
I did this with my 5 year old son this weekend and he can now spot about 8 trees just from their leaves.
Smelling of woodsmoke reminded me of being 11 again :)