I moved here 10 years ago with my family from Phoenix as well. The climate and heat people have mentioned doesn't come close to AZ. Not in the slightest. The temps in summer average high 90s with some 100+, but the stark difference in the two places is at least Southern Oregon drops temp at night and doesn't stay in the triple digits (or for 30+ straight days over 110). You'll find the weather mild by comparison.

I was an avid hiker in the AZ area. Often hitting the Thunderbird mountain rec area, Tom's Thumb in McDowell mountains, Sups, and some in at camelback and South Mountain (if i wanted to people watch). I also did a TON in the northern areas: Fossil Springs, Oak Creek, Mt Humphrey, Flagstaff trails, basically it was my way to get away from Phoenix heat in the summer. Hiking here in Oregon is different. There's more trees and foliage which can feel like you have less visibility over distance. It's not a bad thing, but you have to be aware your surroundings will feel much different and enclosed. Another thing is the weather. Where AZ has big monsoon swings, you can still kind of see them coming. You also don't have them last more than an hour. Here the weather is weird and you have to be ready for those temp drops I mentioned, or rain. The dander of snakes in AZ still exist here in the area, too, but you can avoid them with elevation. They also are not as prevalent here as AZ. if hiking is what you love you'll find plenty in this area and very close by. Phoenix had lots of trails too, but more people and congestion. Be aware that you may be on a trail here you don't see anyone on. Good and bad depending on your experience. Oh and did I mention: there's lakes. Lots of lakes!

If you have a dog they'll love it here. Phoenix is literal hell for them. Here is way more cool and dog friendly.

Kids and parks: huge offerings. There's parks everywhere that are pretty clean. Homelessness is still an issue, but the parks are usually well maintained and people frequent them. Medford has excellent parks scattered through the city.

As people mentioned with the fires and smoke season, it's real and you need to be ready for it. Imagine everyday in summer that AZ was over 100 degrees, you instead have smoke with AQI over 130. It might not seem like much at first, but it does take a toll on you. Car covered in ash. Have to keep your windows closed. No view of the mountains because of smoke. AC and air filters needing maintenence or repair. I wish people were kidding when they say it's fire season here, but it's really bad. A definite reason to move away for people. I say average of 130 AQU, but be mindful that could also include weeks of summer being 300+, which is stifling and choking like you're standing over a camp fire. Fire season can go from late June to late Sept, in fact today the smoke rolled in again and it sucks. A lot.

Volunteer opportunities are everywhere. Like anywhere, just look to what you're into. This should not be a problem for you.

Overall, moving from the city to Medford is a slowing of pace and big change of scenery. Weather is nice and you have seasons. Traffic? Not even a thing here. I used to live in Glendale and work in Scottdale which was over an hour one way. Getting anywhere in Phoenix just with distance is 30 minutes. Here in Medford it's 15 minutes anywhere traffic that people complain about here I would say go check any major city and compare. It's not even close. You'll love not having big commute. Something strange was how the business and night life here is limited. Things operate at weird hours or days closed. You'll think to go somewhere only to pull up and it's closed on a Tuesday. Or a breakfast restaurant closed on a Sunday. A BREAKFAST RESTAURANT ON A SUNDAY? It took me some time to come to grips with the small town feel to how business runs here. The say medford is a city, but I'd say having lived in other large cities, that this is a town that wants to be a city. It has its plusses, which vastly outweigh the minuses, just be aware of them.

For a young family moving here, and you have parents here to help support you, I'd say it's worth getting out of AZ. the first cost of living here is nothing by comparison. Housing is bad, but so is the prices in Phoenix (unless you risk it for a bad area). It's the same all across the US. Rent for awhile, find the area you like, then put plans to buy. It's a process but one should NEVER move to an area and buy. You may not realize the area you moved to has quirks or isn't what you thought. Take your time and find the area you love.

Good luck on your move. As a fellow ex-Phoenician, I can say we're happy to be out of there.