California water temperature in September
| Min (°C/°F) | Avg (°C/°F) | Max (°C/°F) | Current (°C/°F) | |
|---|---|---|---|---|
| Blacks Beach | 17.8 (64) | 19.3 (66.7) | 20.9 (69.5) | 16.3 (61.4) |
| Carlsbad | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 16.3 (61.3) |
| Coronado | 17.8 (64) | 19.3 (66.7) | 20.9 (69.5) | 16.3 (61.4) |
| Del Mar | 17.8 (64) | 19.3 (66.7) | 20.9 (69.5) | 16.3 (61.4) |
| Huntington Beach | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 15.3 (59.5) |
| La Jolla | 17.8 (64) | 19.3 (66.7) | 20.9 (69.5) | 16.3 (61.4) |
| Laguna Beach | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 15.4 (59.8) |
| Lake Tahoe | 12.5 (54.5) | 13.8 (56.8) | 15.1 (59.2) | 6.2 (43.2) |
| Long Beach | 17.3 (63.1) | 18.9 (66) | 20.6 (69) | 15.2 (59.4) |
| Los Angeles | 15.5 (59.8) | 17.1 (62.8) | 18.8 (65.8) | 14.8 (58.7) |
| Malibu | 15.5 (59.8) | 17.1 (62.8) | 18.8 (65.8) | 14.6 (58.3) |
| Malibu Beach | 15.5 (59.8) | 17.1 (62.8) | 18.8 (65.8) | 14.6 (58.3) |
| Mission Bay | 17.8 (64) | 19.3 (66.7) | 20.9 (69.5) | 16.3 (61.4) |
| Monterey | 13.4 (56.1) | 14.5 (58.1) | 15.6 (60.1) | 12.7 (54.9) |
| Newport Beach | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 15.3 (59.5) |
| Ocean Beach | 12.9 (55.1) | 13.8 (56.8) | 14.8 (58.6) | 13 (55.4) |
| Oceanside | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 16.2 (61.2) |
| San Clemente | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 15.9 (60.6) |
| San Diego | 17.8 (64) | 19.3 (66.7) | 20.9 (69.5) | 16.3 (61.3) |
| San Francisco | 12.9 (55.1) | 13.8 (56.8) | 14.8 (58.6) | 12.9 (55.2) |
| San Onofre | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 16 (60.8) |
| Santa Barbara | 14.4 (57.9) | 16.1 (61) | 17.8 (64) | 13.5 (56.3) |
| Santa Catalina Island | 17.3 (63.1) | 18.9 (66) | 20.6 (69) | 15.2 (59.3) |
| Santa Cruz | 13.7 (56.6) | 14.7 (58.5) | 15.8 (60.4) | 12.3 (54.1) |
| Santa Monica | 15.5 (59.8) | 17.1 (62.8) | 18.8 (65.8) | 14.7 (58.4) |
| Tomales Bay | 12.7 (54.8) | 13.4 (56.1) | 14.2 (57.5) | 11.8 (53.2) |
| Ventura | 14.4 (57.9) | 16.1 (61) | 17.8 (64) | 14.3 (57.7) |