| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 39°F | 69°F | 53°F | 4.6" |
| February | 40°F | 68°F | 54°F | 3.4" |
| March | 44°F | 70°F | 56°F | 1.6" |
| April | 46°F | 72°F | 59°F | 1.3" |
| May | 53°F | 73°F | 62°F | 0.8" |
| June | 57°F | 76°F | 66°F | 0.1" |
| July | 60°F | 80°F | 69°F | 0.2" |
| August | 60°F | 81°F | 69°F | 0.1" |
| September | 57°F | 82°F | 69°F | 0.3" |
| October | 50°F | 79°F | 64°F | 1.2" |
| November | 43°F | 75°F | 57°F | 1.6" |
| December | 38°F | 68°F | 52°F | 3.8" |
| Index | Bonsall | 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. |
| Camp Pendleton North, CA | 7,885 | 64 | 28.0% |
| Pala, CA | 1,094 | 64 | 28.0% |
| Escondido, CA | 150,396 | 64 | 28.0% |
| Vista, CA | 100,659 | 64 | 28.0% |
| Camp Pendleton South, CA | 16,618 | 64 | 28.0% |
| Bonsall, CA | 4,194 | 64 | 28.0% |
| City | Population | Air Quality Index | National Avg. |
| Tiptonville, TN | 4,194 | 26 | 48.0% |
| Spindale, NC | 4,193 | 36 | 28.0% |
| Alfred, NY | 4,193 | 35 | 30.0% |
| Red Rock, AZ | 4,196 | 47 | 6.0% |
| Sutton, QC | 4,196 | n/a | |
| Bonsall, CA | 4,194 | 64 | 28.0% |
Here are the best places to live in California
See the best places to live in Bonsall
These are the 10 cheapest cities in California
Most Dangerous States In The US