You can use this simple chart to convert Centigrade to Fahrenheit temperatures quickly.
| Centigrade | Fahrenheit |
| -20 | -4 |
| -15 | 5 |
| -10 | 14 |
| -5 | 23 |
| -2 | 28.4 |
| -1 | 30.2 |
| 0 | 32 |
| 1 | 33.8 |
| 2 | 35.6 |
| 3 | 37.4 |
| 4 | 39.2 |
| 5 | 41 |
| 6 | 42.8 |
| 7 | 44.6 |
| 8 | 46.4 |
| 9 | 48.2 |
| 10 | 50 |
| 15 | 59 |
| 20 | 68 |
| 25 | 77 |
| 30 | 86 |
| 35 | 95 |
| 40 | 104 |
| 45 | 113 |
| 50 | 122 |
| 60 | 140 |
| 70 | 158 |
| 80 | 176 |
| 90 | 194 |
| 100 | 212 |