Hi miki, you can say: It was lovely seeing how all the children had grown since last year. It was neither chilly nor hot, the perfect whether for such an event. ...were all part of the program. Hope this helps! :) I'd be happy to help you with more texts and with improving your English. Please check out my profile and feel free to book a lesson :)

It was a Sports Day at my son’s elementary school. Seeing how all the children have grown up from last year was so pleasurable. - grown since last year - I would not use pleasurable, it doesn’t really give you a pleasure as such. It just makes you happy or it is lovely or lovely to see. You could turn the whole sentence around….. It was really lovely to see how all the children have grown since last year. The weather was beautiful (and it was - not needed) neither chilly nor hot which made the event perfect. Activities such as ball-toss game, sprint, a large ball rolling race and an obstacle race made the whole event real fun.

This sounds good, but instead of saying it's on the program, say it is a part of the program.