| 2026-04-08 | Absorber of UV light |
| 2025-11-19 | Layer wrapping Earth |
| 2024-07-21 | Global protection |
| 2024-02-07 | What offers worldwide protection? |
| 2023-10-16 | Stratosphere layer with a "hole" |
| 2022-11-10 | Kind of layer |
| 2022-05-16 | Vital part of the stratosphere's protective layer |
| 2021-11-13 | ___-friendly (ecolabel) |
| 2021-10-19 | Globe coverer |
| 2021-04-11 | ___ hole |
| 2019-10-29 | It's made of three oxygen atoms |
| 2019-06-08 | It's a gas |
| 2018-12-31 | Another name for O3 (as appropriate to 17-, 25-, 44- and 58-Across?) |
| 2018-09-30 | Air supply |
| 2018-03-19 | Layer of the upper atmosphere |
| 2018-03-06 | O3 |
| 2017-12-29 | ___ hole |
| 2017-11-21 | Absorber of UV rays |
| 2017-02-12 | Worry of stratospheric proportions |
| 2016-10-05 | A greenhouse gas |
| 2016-03-10 | It covers the globe |
| 2015-10-12 | Layer in global warming discussions |
| 2015-06-01 | Part of the atmosphere depleted by CFCs |
| 2015-04-26 | UV light blocker |
| 2015-04-07 | Layer in the stratosphere |
| 2014-10-22 | Form of 10-Down |
| 2014-04-13 | Triatomic oxygen molecule |
| 2012-07-15 | O-O-O |
| 2012-04-15 | Protection around the world? |
| 2011-04-19 | Upper atmosphere layer |
| 2010-02-12 | Thunderstorm product |
| 2009-11-10 | Form of oxygen with a sharp odor |
| 2009-07-19 | Radiation reducer |
| 2009-04-19 | Ultraviolet blocker |
| 2009-01-01 | O3 |
| 2008-12-19 | Gas with a penetrating odor |
| 2008-01-23 | A high flier may fly in it |
| 2007-09-16 | Ultraviolet filter |
| 2007-03-20 | Gas in a layer |
| 2007-02-11 | Earth protector |
| 2006-10-14 | Ultraviolet light filter |
| 2006-04-18 | Kind of layer protecting the earth |
| 2005-12-26 | O3 |
| 2005-03-21 | Atmosphere layer |
| 2004-10-12 | Gas in a layer |
| 2004-06-22 | Earth's ___ layer |
| 2003-02-21 | Thunderstorm residue |
| 2001-12-05 | Form of oxygen |
| 2001-09-15 | Thunderstorm product |
| 2001-04-29 | Ray blocker |
| 2001-01-15 | Ultraviolet ray blocker |
| 2000-12-05 | Odorous oxygen |
| 2000-12-02 | Kind of hole |
| 2000-10-24 | Layer with a hole in it |
| 2000-01-24 | Contents of a sensitive layer |
| 1999-11-29 | Composition of an endangered layer |
| 1999-05-23 | Subject of environmentalist study |
| 1998-08-26 | Earth protector |
| 1998-03-26 | Ultraviolet Index factor |
| 1998-01-23 | What CFC's deplete |
| 1997-10-07 | Kind of layer |
| 1997-09-19 | Thunderstorm product |
| 1996-11-03 | Fresh air, slangily |
| 1996-10-04 | Part of the stratosphere |
| 1996-09-19 | Ultraviolet ray absorber |
| 1996-07-14 | With 33-Down, polar phenomena |
| 1996-06-09 | Kind of layer |
| 1996-05-12 | Stratosphere layer |
| 1995-06-15 | Protective layer |
| 1995-05-21 | _____ hole (modern worry) |
| 1995-02-20 | Layer in the atmosphere |
| 1994-11-09 | Ultraviolet ray absorber |
| 1994-05-13 | Kind of layer |