| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 44°F | 68°F | 56°F | 1.6" |
| February | 45°F | 68°F | 56°F | 1.7" |
| March | 47°F | 70°F | 58°F | 1.1" |
| April | 50°F | 71°F | 60°F | 0.7" |
| May | 55°F | 72°F | 62°F | 0.4" |
| June | 58°F | 76°F | 65°F | 0.0" |
| July | 63°F | 80°F | 69°F | 0.1" |
| August | 63°F | 81°F | 70°F | 0.0" |
| September | 61°F | 81°F | 70°F | 0.2" |
| October | 56°F | 79°F | 66°F | 0.5" |
| November | 50°F | 74°F | 61°F | 0.9" |
| December | 44°F | 67°F | 55°F | 2.0" |
| Index | Spring Valley CDP (Lake County) | California | National |
| Air quality index | 64 | 55 | 42 |
| Pollution index | 45,820,500 | 10,473,190 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 87 |
| Days with moderate air quality | 253 |
| Days w/ poor A.Q. for sensitive groups | 23 |
| Days with unhealthy air quality | 2 |
| Pollutant | Total |
| Arsenic | 1.130% |
| Benzene | 0.410% |
| Carbon Tetrachloride | 0.030% |
| Lead | 0.600% |
| Mercury | 0.080% |
| City | Population | Air Quality Index | National Avg. |
| Eucalyptus Hills, CA | 6,448 | 64 | 28.0% |
| La Mesa, CA | 60,208 | 64 | 28.0% |
| Imperial Beach, CA | 27,334 | 64 | 28.0% |
| National City, CA | 61,342 | 64 | 28.0% |
| Bostonia, CA | 17,532 | 64 | 28.0% |
| Spring Valley CDP (Lake County), CA | 1,154 | 64 | 28.0% |
| City | Population | Air Quality Index | National Avg. |
| Astoria, IL | 1,154 | 40 | 20.0% |
| Hatfield, MA | 1,154 | 40 | 20.0% |
| West Kennebunk, ME | 1,154 | 40 | 20.0% |
| Urbancrest, OH | 1,154 | 46 | 8.0% |
| Richlandtown, PA | 1,154 | 42 | 16.0% |
| Spring Valley CDP (Lake County), CA | 1,154 | 64 | 28.0% |
Here are the best places to live in California
See the best places to live in Spring Valley CDP (Lake County)
These are the 10 cheapest cities in California
Check out the 10 safest cities in California