Click on a day for an hourly weather forecast
The weather in Katy in September is very hot. The average temperatures are between 23°C and 32°C, drinking water regularly is advisable.
You can expect rain for roughly half of the month of September in Katy. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Katy in September 2025.
If you’re planning to visit Katy in the near future, we highly recommend that you review the 14 day weather forecast for Katy before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 16° / 8° | 5 | 25 | 0 | 78 mm | Good | Katy in January |
| February | 18° / 9° | 6 | 23 | 0 | 82 mm | Good | Katy in February |
| March | 22° / 13° | 5 | 26 | 0 | 89 mm | Good | Katy in March |
| April | 26° / 16° | 5 | 25 | 0 | 95 mm | Perfect | Katy in April |
| May | 30° / 20° | 8 | 23 | 0 | 172 mm | Ok | Katy in May |
| June | 33° / 23° | 10 | 20 | 0 | 166 mm | Ok | Katy in June |
| July | 34° / 24° | 10 | 21 | 0 | 152 mm | Bad | Katy in July |
| August | 35° / 25° | 9 | 22 | 0 | 184 mm | Bad | Katy in August |
| September | 32° / 23° | 10 | 20 | 0 | 203 mm | Ok | Katy in September |
| October | 28° / 18° | 6 | 25 | 0 | 129 mm | Perfect | Katy in October |
| November | 21° / 13° | 5 | 25 | 0 | 93 mm | Good | Katy in November |
| December | 18° / 10° | 6 | 25 | 0 | 100 mm | Good | Katy in December |