How important is BMI and how accurate are the online charts?

I have a very active job and I’m on vacation right now. My job sometimes makes it difficult to work out as much as I’d like so I’m taking my 1 & 1/2 months of summer to get in the best shape I can. I’ve gone back to running, about 5 days a week and strength training about 3 days a week. I’m running 4 miles and walking another 2 or 3. I’m 30 years old and I realize that weight loss isn’t as easy as it once was! My goal was to loose about 10lbs this summer. I know that’s a lot but I have the time and energy to dedicate myself to that right now. What concerns me is that even if I loose 10 lbs I’m still at the cusp of being considered “overweight” with a BMI of 25.9.
I eat pretty healthy and I’m even doing weight watchers right now. I’m a vegetarian (and have been for 17 years so don’t try to change me But I eat all kinds of veggies, legumes, dairy, soy… and try to make sure I eat sufficient protein. I think health should be the most important thing, but my BMI concerns me.