San Francisco in September
Find out everything about the water temperature in San Francisco 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:
83.0 °F
Average:
86.1 °F
Maximum:
87.7 °F
Sea water temperature in San Francisco in September
In the city of San Francisco, the month of September is a great time for swimming. The minimum recorded temperature during this month was 83.0°F on September 28, 2016, with an average temperature being 86.1°F and a maximum temperature reaching 87.7°F on September 5, 2017.
| Date | 10 years average | 2025 | 2024 |
|---|---|---|---|
| Sep 1 | 86.2°F | 85.6°F | 87.0°F |
| Sep 2 | 85.9°F | 85.4°F | 86.8°F |
| Sep 3 | 86.0°F | 85.6°F | 87.3°F |
| Sep 4 | 86.1°F | 85.8°F | 87.3°F |
| Sep 5 | 86.2°F | 85.9°F | 86.8°F |
| Sep 6 | 86.1°F | 85.8°F | 86.5°F |
| Sep 7 | 86.3°F | 85.9°F | 86.5°F |
| Sep 8 | 86.2°F | 85.3°F | 86.1°F |
| Sep 9 | 86.3°F | 85.0°F | 87.0°F |
| Sep 10 | 86.3°F | 84.7°F | 86.9°F |
| Sep 11 | 86.3°F | 84.7°F | 86.8°F |
| Sep 12 | 86.1°F | 84.7°F | 86.6°F |
| Sep 13 | 86.0°F | 84.7°F | 86.5°F |
| Sep 14 | 86.0°F | 85.7°F | 86.3°F |
| Sep 15 | 86.0°F | 85.6°F | 86.2°F |
| Sep 16 | 85.9°F | 85.1°F | 86.0°F |
| Sep 17 | 85.9°F | 85.1°F | 85.9°F |
| Sep 18 | 85.9°F | 84.6°F | 85.9°F |
| Sep 19 | 86.2°F | 86.1°F | 85.8°F |
| Sep 20 | 86.2°F | 86.1°F | 85.8°F |
| Sep 21 | 86.0°F | 86.1°F | 85.7°F |
| Sep 22 | 85.9°F | 85.4°F | 85.7°F |
| Sep 23 | 86.2°F | 86.7°F | 86.7°F |
| Sep 24 | 86.0°F | 85.1°F | 86.3°F |
| Sep 25 | 86.0°F | 85.2°F | 86.1°F |
| Sep 26 | 86.0°F | 85.2°F | 86.4°F |
| Sep 27 | 85.8°F | 85.3°F | 86.3°F |
| Sep 28 | 85.8°F | 85.4°F | 86.4°F |
| Sep 29 | 85.9°F | 84.9°F | 86.4°F |
| Sep 30 | 85.9°F | 85.5°F | 86.1°F |
In San Francisco, the water temperature is comfortable for swimming all year round.
The warmest water in San Francisco was recorded on June 5, 2017, reaching a 88.2°F. While the coldest temperature occurred on February 3, 2019, dipping to 79.8°F. The average readings by season are 82.9°F in Winter, 84.1°F in Spring, 86.3°F in Summer, and 85.8°F in Autumn.
In September, the temperature remains consistent with August's average reading of 86.1°F. However, in October, it rises to an average of 86.1°F.
Popular neighboring cities and resorts
| City | Water temperature* | Distance** |
|---|---|---|
| Santiago |
81.9°F
|
6mi |
| Merida |
81.6°F
|
21mi |
| San Juan |
81.6°F
|
27mi |
| San Francisco |
82.4°F
|
34mi |
* current water temperature in this city
** straight line distance from San Francisco