Click on a day for an hourly weather forecast
The temperatures in Palo Alto in September are comfortable with low of 17°C and and high up to 27°C.
As it is almost never rain during September in Palo Alto the weather is perfect for hanging out outside and exploring all that Palo Alto has to offer.
Our weather forecast can give you a great sense of what weather to expect in Palo Alto in September 2025.
If you’re planning to visit Palo Alto in the near future, we highly recommend that you review the 14 day weather forecast for Palo Alto before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 16° / 9° | 4 | 27 | 0 | 85 mm | Good | Palo Alto in January |
| February | 17° / 9° | 4 | 24 | 0 | 86 mm | Good | Palo Alto in February |
| March | 17° / 9° | 5 | 26 | 0 | 88 mm | Good | Palo Alto in March |
| April | 19° / 10° | 2 | 28 | 0 | 35 mm | Good | Palo Alto in April |
| May | 21° / 12° | 1 | 30 | 0 | 15 mm | Good | Palo Alto in May |
| June | 25° / 15° | 0 | 30 | 0 | 5 mm | Perfect | Palo Alto in June |
| July | 27° / 16° | 0 | 31 | 0 | 1 mm | Perfect | Palo Alto in July |
| August | 27° / 17° | 0 | 31 | 0 | 1 mm | Perfect | Palo Alto in August |
| September | 27° / 17° | 0 | 30 | 0 | 4 mm | Perfect | Palo Alto in September |
| October | 24° / 15° | 1 | 30 | 0 | 28 mm | Perfect | Palo Alto in October |
| November | 19° / 12° | 3 | 28 | 0 | 44 mm | Good | Palo Alto in November |
| December | 15° / 9° | 5 | 26 | 0 | 71 mm | Good | Palo Alto in December |