| 2025年 | 2026年 | 平年値 | |
| 5-8 | 15.3 | 15.7 | 15.3 |
| 5-9 | 15.3 | 16.2 | 15.3 |
| 5-10 | 15.4 | 16.2 | 15.4 |
| 5-11 | 15.5 | 16.2 | 15.5 |
| 5-12 | 15.6 | 16.5 | 15.6 |
| 5-13 | 15.7 | --- | 15.7 |
| 5-14 | 16 | 17.5 | 16 |
| 5-15 | 16.2 | 17.4 | 16.2 |
| 5-16 | 16.2 | 17.7 | 16.2 |
| 5-17 | 16.3 | 17.4 | 16.3 |
| 5-18 | 16.3 | 18.2 | 16.3 |
| 5-19 | 16.7 | 17.7 | 16.7 |
| 5-20 | 16.9 | 17.9 | 16.9 |
| 5-21 | 17 | 17.8 | 17 |
| 5-22 | 17.1 | 18.4 | 17.1 |