How comfortable/uncomfortable is the weather in late June in Phoenix? If we are staying at one of the resorts, possibly the Biltmore, is it too hot to do outdoor activities? Thanks for any replies

That depends on you, WIlley. No simple answer.
Personally, I love the heat (as long as it's dry) and lived in Phoenix for a few years a while back. We often vacation there in June when the resort rates go down because others don't find it palatable.
It's hot in June, of course. Usually over 100, sometimes 110+ (getting slightly warmer each year as the metro area builds out and more cement (great retainer of heat) is added).
Daytime is not always pleasant, but the mornings and evenings in the summer can be really great.
Biltmore is nice. Check the Phoenician and Princess for specials. I find them a bit better than the Biltmore.

Just like BC said it is hot and depends on how well you tolerate the heat.
We have visited PHX just about every summer since my parents retired there 20 some years ago. Walking, sightseeing, golf and such are best early in the morning. Tennis, swimming and the more strenous activities, in the evening, after sunset is best. The afternoons are best for indoor persuits shopping (A/C malls), napping, etc.

Of course, this is just my opinion and I'm an Easterner.

I just was in Phoenix yesterday, and I would say it's horridly uncomfortable. But it all depends on how you feel about
heat. It was way over a hundred, and it may be dry heat, but boy is it hot. At a certain point it doesn't matter whether its wet or dry anymore. So I think Phoenix in June would be a foretaste of hell, but if you like heat it may not be so bad.

The Biltmore is a great hotel and terrific location for getting around to see the sights. The thing about the heat here is that it doesn't cool off much at night, so when you open the door in the a.m., it feels a bit like a blast furnace. Most of us are used to it and look forward to it, but it is not for everyone. Friends and relatives of ours from the UK that visit in the summer love it and find it preferable to humid heat.

Take a cue - our outdoor/indoor baseball stadium is airconditioned! Nevertheless, as someone else has said, it is preferable to most people who have ever endured humidity with heat.
There are lots of fun waterparks here and many indoor activities to keep busy with . I agree that the Princess or the Phoenician are preferable to the Biltmore. The Princess is away from alot of the hub-bub. The Hyatt at Gainey Ranch is beautiful and has a neat restaurant that includes a gondola ride around the grounds with your Italian dinner. Have a great visit.

As the saying goes "Yes, but it's a dry heat".....Phoenix in June is going to very hot and VERY dry. If you are used to alot of humidity, the dryness will most likely let to you as you get used to it. Most activities outside need to be done in the very early morning or in the evening. It really depends on how you can take heat over 100 deg. probably every day. The evening are really very nice - they stay warm so that you can sit outside, swim, etc.

I must agree with Charles. When the thermometer says 112 degrees, it doesn't matter whether it is humid or dry. Tell that to the chicken you have cooking in the oven! I am used to a lot of humidity Spiry, but I'm not used to 112 degrees no matter what the moisture content. BUT...you still should be able to find some indoor things to do, limiting your outdoor time to early and VERY late.

One of the things I always laugh about when in Phoenix in the summer is the comment "but it's dry." I come from Houston, where it's not dry, but take it from me, 110 is an oven, it doesn't matter if it's dry or not. I am used to heat, but I find it impossible to do much except stay in the pool with A LOT of sunscreen on. We were in Phoenix last at the end of May, and it was 105 already at that time.

It is a nice city, Scottsdale is really a great spot for a vacation, but the heat is hard to take.

Good luck.