Click on a day for an hourly weather forecast
The temperatures in Fullerton in October are comfortable with low of 17°C and and high up to 27°C.
You can expect a few rainy days in Fullerton during October, but usually the weather is comfortable in October.
Our weather forecast can give you a great sense of what weather to expect in Fullerton in October 2025.
If you’re planning to visit Fullerton in the near future, we highly recommend that you review the 14 day weather forecast for Fullerton before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 20° / 10° | 3 | 28 | 0 | 63 mm | Good | Fullerton in January |
| February | 20° / 10° | 3 | 26 | 0 | 52 mm | Good | Fullerton in February |
| March | 21° / 11° | 3 | 28 | 0 | 47 mm | Good | Fullerton in March |
| April | 22° / 13° | 1 | 29 | 0 | 17 mm | Good | Fullerton in April |
| May | 23° / 14° | 1 | 30 | 0 | 7 mm | Perfect | Fullerton in May |
| June | 26° / 16° | 0 | 30 | 0 | 1 mm | Perfect | Fullerton in June |
| July | 29° / 19° | 1 | 31 | 0 | 2 mm | Good | Fullerton in July |
| August | 30° / 20° | 0 | 31 | 0 | 1 mm | Good | Fullerton in August |
| September | 30° / 20° | 0 | 30 | 0 | 4 mm | Good | Fullerton in September |
| October | 27° / 17° | 1 | 30 | 0 | 12 mm | Perfect | Fullerton in October |
| November | 23° / 13° | 2 | 28 | 0 | 19 mm | Perfect | Fullerton in November |
| December | 19° / 10° | 4 | 27 | 0 | 71 mm | Good | Fullerton in December |