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) | 23 (73.4) |
| Carlsbad | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 23.3 (73.9) |
| Coronado | 17.8 (64) | 19.3 (66.7) | 20.9 (69.5) | 22.4 (72.4) |
| Del Mar | 17.8 (64) | 19.3 (66.7) | 20.9 (69.5) | 23.1 (73.6) |
| Huntington Beach | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 22 (71.6) |
| La Jolla | 17.8 (64) | 19.3 (66.7) | 20.9 (69.5) | 23 (73.3) |
| Laguna Beach | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 22.3 (72.2) |
| Lake Tahoe | 12.5 (54.5) | 13.8 (56.8) | 15.1 (59.2) | 6.3 (43.4) |
| Long Beach | 17.3 (63.1) | 18.9 (66) | 20.6 (69) | 22 (71.5) |
| Los Angeles | 15.5 (59.8) | 17.1 (62.8) | 18.8 (65.8) | 21.5 (70.7) |
| Malibu | 15.5 (59.8) | 17.1 (62.8) | 18.8 (65.8) | 20.7 (69.3) |
| Malibu Beach | 15.5 (59.8) | 17.1 (62.8) | 18.8 (65.8) | 21 (69.7) |
| Mission Bay | 17.8 (64) | 19.3 (66.7) | 20.9 (69.5) | 22.8 (73) |
| Monterey | 13.4 (56.1) | 14.5 (58.1) | 15.6 (60.1) | 14.5 (58.2) |
| Newport Beach | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 22.1 (71.8) |
| Ocean Beach | 12.9 (55.1) | 13.8 (56.8) | 14.8 (58.6) | 14.7 (58.5) |
| Oceanside | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 23.2 (73.8) |
| San Clemente | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 23 (73.3) |
| San Diego | 17.8 (64) | 19.3 (66.7) | 20.9 (69.5) | 22.4 (72.2) |
| San Francisco | 12.9 (55.1) | 13.8 (56.8) | 14.8 (58.6) | 14.3 (57.8) |
| San Onofre | 17.7 (63.8) | 19.3 (66.7) | 21 (69.7) | 23.1 (73.5) |
| Santa Barbara | 14.4 (57.9) | 16.1 (61) | 17.8 (64) | 19.3 (66.8) |
| Santa Catalina Island | 17.3 (63.1) | 18.9 (66) | 20.6 (69) | 21 (69.8) |
| Santa Cruz | 13.7 (56.6) | 14.7 (58.5) | 15.8 (60.4) | 13.7 (56.7) |
| Santa Monica | 15.5 (59.8) | 17.1 (62.8) | 18.8 (65.8) | 21.9 (71.4) |
| Tomales Bay | 12.7 (54.8) | 13.4 (56.1) | 14.2 (57.5) | 13.3 (55.9) |
| Ventura | 14.4 (57.9) | 16.1 (61) | 17.8 (64) | 19.6 (67.2) |