Shimonoseki in September
Find out everything about the water temperature in Shimonoseki 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:
74.3 °F
Average:
79.6 °F
Maximum:
86.9 °F
Sea water temperature in Shimonoseki in September
In the city of Shimonoseki, the month of September is a great time for swimming. The minimum recorded temperature during this month was 74.3°F on September 30, 2015, with an average temperature being 79.6°F and a maximum temperature reaching 86.9°F on September 2, 2025.
| Date | 10 years average | 2025 | 2024 |
|---|---|---|---|
| Sep 1 | 82.2°F | 86.8°F | 82.0°F |
| Sep 2 | 81.9°F | 86.9°F | 81.7°F |
| Sep 3 | 81.5°F | 85.4°F | 82.2°F |
| Sep 4 | 81.6°F | 85.8°F | 81.8°F |
| Sep 5 | 81.4°F | 85.8°F | 81.3°F |
| Sep 6 | 81.4°F | 85.9°F | 81.2°F |
| Sep 7 | 81.1°F | 85.6°F | 82.8°F |
| Sep 8 | 80.6°F | 85.7°F | 82.2°F |
| Sep 9 | 80.5°F | 85.7°F | 82.9°F |
| Sep 10 | 80.4°F | 85.1°F | 83.0°F |
| Sep 11 | 80.4°F | 84.7°F | 84.6°F |
| Sep 12 | 80.5°F | 84.9°F | 85.0°F |
| Sep 13 | 80.2°F | 84.7°F | 84.7°F |
| Sep 14 | 80.1°F | 84.0°F | 83.7°F |
| Sep 15 | 79.9°F | 84.3°F | 83.6°F |
| Sep 16 | 79.9°F | 84.7°F | 84.1°F |
| Sep 17 | 79.8°F | 86.0°F | 84.3°F |
| Sep 18 | 79.6°F | 85.5°F | 83.9°F |
| Sep 19 | 79.3°F | 84.4°F | 84.7°F |
| Sep 20 | 79.0°F | 84.1°F | 83.8°F |
| Sep 21 | 78.8°F | 83.9°F | 83.2°F |
| Sep 22 | 78.5°F | 83.1°F | 82.5°F |
| Sep 23 | 78.2°F | 82.6°F | 82.3°F |
| Sep 24 | 77.7°F | 82.0°F | 81.1°F |
| Sep 25 | 77.5°F | 81.7°F | 80.4°F |
| Sep 26 | 77.4°F | 81.0°F | 80.1°F |
| Sep 27 | 77.4°F | 80.5°F | 79.7°F |
| Sep 28 | 77.5°F | 81.1°F | 81.7°F |
| Sep 29 | 77.5°F | 81.2°F | 81.1°F |
| Sep 30 | 77.2°F | 81.7°F | 80.6°F |
In Shimonoseki, the months July through September offer comfortable swimming conditions, which amounts to 112 swimming days.
The warmest water in Shimonoseki was recorded on September 2, 2025, reaching a 86.9°F. While the coldest temperature occurred on March 10, 2025, dipping to 48.5°F. The average readings by season are 57.4°F in Winter, 59.3°F in Spring, 77.5°F in Summer, and 73.3°F in Autumn.
September's average temperature is a slight drop from August's average of 82.6°F. In October, the temperature is expected to decrease further, potentially averaging around 73.4°F.
Popular neighboring cities and resorts
| City | Water temperature* | Distance** |
|---|---|---|
| Kitakyushu |
81.1°F
|
9mi |
| Fukuoka |
77.5°F
|
39mi |
| Beppu |
77.2°F
|
57mi |
| Ōita |
77.1°F
|
63mi |
* current water temperature in this city
** straight line distance from Shimonoseki