Niihama in September
Find out everything about the water temperature in Niihama in September. Average, minimum and maximum recorded temperatures as well as daily temperature in September for the last two years. Compare the current month's sea temperature data with other months of the year.
Water temperature in September
Minimum:
75.7 °F
Average:
81.3 °F
Maximum:
88.0 °F
Sea water temperature in Niihama in September
In the city of Niihama, the month of September is a great time for swimming. The minimum recorded temperature during this month was 75.7°F on September 30, 2015, with an average temperature being 81.3°F and a maximum temperature reaching 88.0°F on September 2, 2025.
| Date | 10 years average | 2025 | 2024 |
|---|---|---|---|
| Sep 1 | 83.5°F | 86.2°F | 83.7°F |
| Sep 2 | 83.3°F | 88.0°F | 83.6°F |
| Sep 3 | 83.1°F | 87.5°F | 83.3°F |
| Sep 4 | 82.9°F | 87.0°F | 82.8°F |
| Sep 5 | 82.7°F | 86.0°F | 83.8°F |
| Sep 6 | 82.5°F | 85.3°F | 83.9°F |
| Sep 7 | 82.5°F | 85.2°F | 85.2°F |
| Sep 8 | 82.1°F | 85.2°F | 84.1°F |
| Sep 9 | 82.1°F | 85.2°F | 84.5°F |
| Sep 10 | 82.3°F | 85.7°F | 84.7°F |
| Sep 11 | 82.5°F | 85.2°F | 85.7°F |
| Sep 12 | 82.2°F | 85.4°F | 84.4°F |
| Sep 13 | 82.3°F | 84.9°F | 84.9°F |
| Sep 14 | 82.2°F | 85.3°F | 85.7°F |
| Sep 15 | 81.7°F | 84.4°F | 85.0°F |
| Sep 16 | 81.6°F | 85.3°F | 84.8°F |
| Sep 17 | 81.4°F | 85.9°F | 84.3°F |
| Sep 18 | 81.6°F | 87.0°F | 85.5°F |
| Sep 19 | 81.2°F | 86.1°F | 85.3°F |
| Sep 20 | 81.1°F | 85.1°F | 87.1°F |
| Sep 21 | 80.8°F | 84.3°F | 86.3°F |
| Sep 22 | 80.5°F | 83.2°F | 85.4°F |
| Sep 23 | 80.2°F | 84.1°F | 84.6°F |
| Sep 24 | 79.8°F | 83.3°F | 84.2°F |
| Sep 25 | 79.4°F | 82.5°F | 83.4°F |
| Sep 26 | 79.3°F | 81.8°F | 84.3°F |
| Sep 27 | 79.2°F | 81.7°F | 84.0°F |
| Sep 28 | 79.0°F | 81.6°F | 83.3°F |
| Sep 29 | 79.0°F | 81.5°F | 82.7°F |
| Sep 30 | 78.8°F | 81.3°F | 82.4°F |
In Niihama, the months July through October offer comfortable swimming conditions, which amounts to 122 swimming days.
The warmest water in Niihama was recorded on August 3, 2024, reaching a 88.8°F. While the coldest temperature occurred on February 26, 2022, dipping to 48.0°F. The average readings by season are 56.1°F in Winter, 58.7°F in Spring, 78.6°F in Summer, and 74.8°F in Autumn.
September's average temperature is a slight drop from August's average of 84.0°F. In October, the temperature is expected to decrease further, potentially averaging around 75.3°F.
Popular neighboring cities and resorts
| City | Water temperature* | Distance** |
|---|---|---|
| Saijō |
80.7°F
|
8mi |
| Matsuyama |
76.8°F
|
32mi |
| Marugame |
81.8°F
|
35mi |
| Fukuyama |
81.5°F
|
36mi |
| Takamatsu |
81.8°F
|
50mi |
| Kurashiki |
82.3°F
|
50mi |
| Hiroshima |
78.1°F
|
58mi |
| Okayama |
81.2°F
|
60mi |
* current water temperature in this city
** straight line distance from Niihama