I tested my FTP about two months ago on my trainer. Now when I am outside riding I rarely get to my FTP and if I do I feel like I am way over FTP. Can this be affected by wind, road conditions etc? I know my PT was calibrated and currently is calibrated, but it seems odd to me. Thanks.

Your FTP is guaranteed to have changed (it's never static). You need to test again. Any other statements are guesses.

Just get recovered and do a real test again. If you want to test on the trainer again, that's fine, but you should start working towards a standard test.

FWIW: I don't really test FTP any more. I just know how I'm doing on certain threshold workouts, and spot check with an occasional 20-minute effort. That's enough for me to set zones/interval targets, and enough for me to track performance and training effectiveness. I'd recommend you do the testing while you're getting started in the power stuff though.

As Bill Parcels used to say, "You are what your record is". If you have been testing it recently, and it is calibrated, then that if your power output. I would take your multiple readings from the PT (again - assuming it is calibrated) more than one test on a trainer. I would look more towards changes in sleep, diet, and potentially over-training as reasons, not wind/road conditions (why a power meter is more effective than HR/Avg Speed combo for determining effectiveness.

So if my ftp is say 240, then it shouldn't matter if it is windy or the roads are bad or hilly, if I am feeling pretty good (i.e. ate well, slept well, not overtrained) I should still be able to have 240 as an FTP?

Yes - that is why training with power is so effective. Your ability to ride in a headwind (powerwise) will be the same as riding in a tail wind. Speed may change, but power is what it is. Again - rather than look for external reasons for the change (which as WR said, it will always fluctuate), look for physiological changes. Weight gain/loss, eating habits, sleep, training schedule. My power numbers one week fell 80 watts after a 5 day stretch of brutally tough riding (not in my training plan...why group rides should not be your only training). I panicked. However, through rest, eating well, and taking it easier on the bike, my legs no longer feel dead, and my power numbers are up. I raced two crits this weekend, and my legs felt okay and last weeks power test proved that.

Thanks guys. Today I was doing Threshold intervals and was able to actually ride around my tested FTP on a windy day, so I guess it was just me.