| Clue | Source | Date |
|---|---|---|
| Monthly payment that might increase in the winter | ||
| Monthly utility statement | New York Times | 16 Dec 2021 |
| It's higher when it's colder | LA Times Daily | 12 Sep 2020 |
| It's higher when it's colder | ||
| Monthly utility payment | New York Times | 27 Aug 2019 |
| Statement with a meter reading | ||
| Monthly utility payment | ||
| It may go up in winter | New York Times | 01 Sep 2017 |
| Country houses like rough monthly charge? | The Telegraph Toughie | 18 Jan 2017 |
| It may go up in winter | ||
| Certain utility statement |