I haven't tuned my piano in more than a year. I always tune it myself. Is it safe to do after this long

I practice 6-7 hours every day or when I don't, I travel around. We have strict neighbors. A lot of factors delayed the tuning of my several decade-old C. Bechstein and by now I'm scared if it's even safe to attempt to tune it or I'll break strings. I was planning to once the heatwave passed. I have a competition in September and I wanted to do it before. I know, it already should've been done in spring, but no point dwelling on that