Click on a day for an hourly weather forecast
The temperatures in Seaside in September are comfortable with low of 14°C and and high up to 23°C.
There is little to no rain in Seaside during September, so it’s a lot easier to explore the city. Just remember to dress in warm layers, as it can still get pretty chilly.
Our weather forecast can give you a great sense of what weather to expect in Seaside in September 2025.
If you’re planning to visit Seaside in the near future, we highly recommend that you review the 14 day weather forecast for Seaside before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 16° / 8° | 4 | 27 | 0 | 107 mm | Good | Seaside in January |
| February | 16° / 8° | 4 | 24 | 0 | 93 mm | Good | Seaside in February |
| March | 16° / 8° | 5 | 26 | 0 | 97 mm | Good | Seaside in March |
| April | 17° / 9° | 3 | 27 | 0 | 39 mm | Good | Seaside in April |
| May | 18° / 10° | 1 | 30 | 0 | 17 mm | Good | Seaside in May |
| June | 21° / 12° | 0 | 30 | 0 | 6 mm | Good | Seaside in June |
| July | 22° / 13° | 0 | 31 | 0 | 5 mm | Good | Seaside in July |
| August | 23° / 14° | 0 | 31 | 0 | 3 mm | Perfect | Seaside in August |
| September | 23° / 14° | 0 | 30 | 0 | 6 mm | Perfect | Seaside in September |
| October | 21° / 13° | 1 | 30 | 0 | 28 mm | Good | Seaside in October |
| November | 18° / 10° | 3 | 27 | 0 | 52 mm | Good | Seaside in November |
| December | 15° / 8° | 5 | 26 | 0 | 99 mm | Good | Seaside in December |