| 2025年 | 2026年 | 平年値 | |
| 5-17 | 15.7 | 16.7 | 15.8 |
| 5-18 | --- | 17.5 | 16.1 |
| 5-19 | --- | 17.1 | 16.2 |
| 5-20 | 16.1 | 17.2 | 16.3 |
| 5-21 | 16.2 | 17.1 | 16.4 |
| 5-22 | 16.4 | 17.8 | 16.6 |
| 5-23 | --- | 17.8 | 18.5 |
| 5-24 | 16.3 | 18.1 | 18.3 |
| 5-25 | 16.7 | 17.8 | 17.9 |
| 5-26 | --- | 17.7 | 17.4 |
| 5-27 | --- | 17.9 | 17.2 |
| 5-28 | --- | 18 | 17.6 |
| 5-29 | --- | 18.4 | 17.9 |
| 5-30 | --- | 18.7 | 18 |
| 5-31 | --- | 18.6 | 17.9 |