Thank you for submitting your question. From what I can tell from the photos, I see fire blight as well as some possible hail damage to the leaves. As far as the hail damage goes, it is just aesthetic on the leaves. For the fire blight, trimming now can be a problem, because you can spread the bacterium with pruning tools. If you prune only the affected/dead area and not cut into any healthy and live tissue, you can remove some of the problem. The better time is to wait until the dormant season, where you can prune without concern for spreading the disease.

Very important: If you prune now, you must sterilize your tools with 70% rubbing alcohol between EVERY cut.

From CSU Extension’s fact sheet on Fire Blight: “There is no cure for this disease, so prevention is the best solution for the management of fire blight. Fire blight management methods include: planting resistant varieties, implementing cultural practices that favor growth of the plant rather than the pathogen, pruning to remove infected plant parts, and chemical sprays. Using resistant varieties is the most effective prevention method. Spraying chemicals is not recommended for homeowners because of chemical availability, potential phytoxicity and the critical timing of sprays.”

Here is the link to our fact sheet: https://extension.colostate.edu/topic-areas/yard-garden/fire-blight-2-907/