Click on a day for an hourly weather forecast
The temperatures in New Plymouth in September are quite cold with temperatures between 9°C and 14°C, warm clothes are a must.
You can expect rain for roughly half of the month of September in New Plymouth. 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 New Plymouth in September 2025.
If you’re planning to visit New Plymouth in the near future, we highly recommend that you review the 14 day weather forecast for New Plymouth before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 21° / 15° | 4 | 27 | 0 | 102 mm | Good | New Plymouth in January |
| February | 21° / 15° | 4 | 24 | 0 | 115 mm | Good | New Plymouth in February |
| March | 20° / 14° | 5 | 26 | 0 | 123 mm | Good | New Plymouth in March |
| April | 18° / 13° | 6 | 24 | 0 | 158 mm | Good | New Plymouth in April |
| May | 16° / 11° | 7 | 24 | 0 | 213 mm | Ok | New Plymouth in May |
| June | 14° / 10° | 9 | 21 | 0 | 219 mm | Ok | New Plymouth in June |
| July | 13° / 9° | 8 | 23 | 0 | 207 mm | Bad | New Plymouth in July |
| August | 13° / 9° | 10 | 21 | 0 | 213 mm | Bad | New Plymouth in August |
| September | 14° / 9° | 10 | 20 | 0 | 220 mm | Ok | New Plymouth in September |
| October | 15° / 10° | 8 | 23 | 0 | 165 mm | Ok | New Plymouth in October |
| November | 17° / 12° | 7 | 23 | 0 | 138 mm | Ok | New Plymouth in November |
| December | 19° / 14° | 8 | 23 | 0 | 151 mm | Ok | New Plymouth in December |