My boy used to spend all morning outside as he was at a Waldkindergarten in Germany, where they had no indoors! That was great and he loved it, regardless of the weather. In fact, rain was welcomed as that meant lots of mud and puddles :)
Back in England, there is no equivalent and his current nursery has them playing outside for an hour every morning unless it's raining when they stay in. He does spend a large part of the afternoon in our garden though, but as it's very small he doesn't get to run around as much as he would like, it's time spent mostly digging up the lawn (shhh don't tell my husband!) and doing chalk drawings on the terrace. I try to take him to the park but haven't been feeling up to it recently.
But I do think it is important for small children particularly to be out as much as possible, one hour doesn't sound like enough time to me!