| 2025年 | 2026年 | 平年値 | |
| 5-17 | 15.8 | 17.3 | 15.8 |
| 5-18 | 15.9 | 17.8 | 15.9 |
| 5-19 | 16.5 | 17.1 | 16.5 |
| 5-20 | 16.8 | 17.3 | 16.8 |
| 5-21 | 16.6 | 17.3 | 16.6 |
| 5-22 | 16.7 | 18.3 | 16.7 |
| 5-23 | 16.8 | 18.1 | 16.8 |
| 5-24 | 16.6 | 18.1 | 16.6 |
| 5-25 | 17 | 18.1 | 17 |
| 5-26 | 17.1 | 18 | 17.1 |
| 5-27 | 17 | 18.1 | 17 |
| 5-28 | 17.1 | 18.1 | 17.1 |
| 5-29 | 17.1 | 18.6 | 17.1 |
| 5-30 | 17.3 | 18.9 | 17.3 |
| 5-31 | 17.6 | --- | 17.6 |