| 日期 | 天气 | 高/低 | 降水 |
|---|---|---|---|
| 2026-09-01 | 小毛毛雨 | 29°/23° | 1.6 mm |
| 2026-09-02 | 小毛毛雨 | 31°/25° | 1.6 mm |
| 2026-09-03 | 雷阵雨 | 32°/24° | 7.6 mm |
| 2026-09-04 | 大毛毛雨 | 27°/23° | 4.8 mm |
| 2026-09-05 | 中阵雨 | 25°/20° | 33.1 mm |
| 2026-09-06 | 强阵雨 | 22°/19° | 101.8 mm |
| 2026-09-07 | 强阵雨 | 23°/20° | 195.2 mm |
| 2026-09-08 | 毛毛雨 | 30°/22° | 0.8 mm |
| 2026-09-09 | 中阵雨 | 33°/21° | 17.9 mm |
| 2026-09-10 | 强阵雨 | 21°/18° | 23.6 mm |
| 2026-09-11 | 中阵雨 | 20°/18° | 32.4 mm |
| 2026-09-12 | 中阵雨 | 22°/20° | 6.4 mm |
| 2026-09-13 | 小毛毛雨 | 27°/20° | 0.2 mm |
| 2026-09-14 | 毛毛雨 | 31°/22° | 0.8 mm |
| 2026-09-15 | 强阵雨 | 26°/21° | 29.6 mm |
| 2026-09-16 | 强阵雨 | 22°/19° | 55.0 mm |
| 2026-09-17 | 中阵雨 | 23°/19° | 14.8 mm |
| 2026-09-18 | 阴 | 25°/19° | 0.0 mm |
| 2026-09-19 | 小毛毛雨 | 26°/21° | 0.3 mm |
| 2026-09-20 | 强阵雨 | 23°/20° | 59.3 mm |
| 2026-09-21 | 强阵雨 | 25°/20° | 68.0 mm |
| 2026-09-22 | 小毛毛雨 | 29°/23° | 0.3 mm |
| 2026-09-23 | 小毛毛雨 | 24°/20° | 1.2 mm |
| 2026-09-24 | 毛毛雨 | 29°/20° | 1.6 mm |
| 2026-09-25 | 大毛毛雨 | 27°/22° | 2.9 mm |
| 2026-09-26 | 阵雨 | 22°/17° | 15.5 mm |
| 2026-09-27 | 阴 | 24°/18° | 0.0 mm |
| 2026-09-28 | 大毛毛雨 | 23°/21° | 3.8 mm |
| 2026-09-29 | 中阵雨 | 22°/17° | 39.9 mm |
| 2026-09-30 | 中雨 | 20°/17° | 13.9 mm |
2026年09月立川市共记录 30 天，平均最高 25℃、最低 20℃，降水日 28 天。