open air 
noun
A free or unenclosed space outdoors: getting out in the open air...
- As of Monday, private homes, the open air or special places reserved for smokers will be the only places to light up.
- But I do have the open air of the roof and a view to see what is going on in the city while I work.
- I sit in the shade mostly, looking out at the sun, but even so the effect of the open air and reflected sunshine is weathering my skin nicely.
adjective
Located or taking place out of doors: an open-air swimming pool...
- Skaters could get their outdoor fun after all, despite York's first open-air ice rink closing over Christmas.
- Four thousand attended an open-air service, and commemorative saplings were planted in Cross Roads Park.
- The large glass windows at the front are also being replaced so that they can open up to give drinkers a new open-air experience in good weather.
Synonyms
outdoor, out-of-doors, outside, al fresco, in the open air;
French en plein air;
Italian al fresco
rare hypaethral