| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 37°F | 60°F | 47°F | 5.6" |
| February | 41°F | 64°F | 52°F | 4.8" |
| March | 45°F | 69°F | 56°F | 4.6" |
| April | 47°F | 74°F | 60°F | 2.5" |
| May | 52°F | 82°F | 67°F | 0.7" |
| June | 57°F | 91°F | 74°F | 0.3" |
| July | 60°F | 96°F | 77°F | 0.0" |
| August | 59°F | 95°F | 75°F | 0.0" |
| September | 56°F | 92°F | 73°F | 0.1" |
| October | 50°F | 81°F | 64°F | 1.9" |
| November | 43°F | 68°F | 54°F | 2.3" |
| December | 37°F | 59°F | 47°F | 4.6" |
| Index | Vacaville | California | National |
| Air quality index | 35 | 55 | 42 |
| Pollution index | 2,457,150 | 10,473,190 | 2,726,193 |
| Measurement | Total |
| Days measured | 363 |
| Days with good air quality | 330 |
| Days with moderate air quality | 31 |
| Days w/ poor A.Q. for sensitive groups | 2 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.080% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.010% |
| Mercury | 0.020% |
| City | Population | Air Quality Index | National Avg. |
| Elmira, CA | 234 | 35 | 30.0% |
| Fairfield, CA | 116,544 | 35 | 30.0% |
| Lemon Hill, CA | 15,104 | 35 | 30.0% |
| Green Valley CDP (Los Angeles County), CA | 1,000 | 35 | 30.0% |
| Moskowite Corner, CA | 69 | 35 | 30.0% |
| Vacaville, CA | 99,958 | 35 | 30.0% |
| City | Population | Air Quality Index | National Avg. |
| Kenosha, WI | 99,767 | 39 | 22.0% |
| San Angelo, TX | 100,509 | 28 | 44.0% |
| Tuscaloosa, AL | 100,633 | 35 | 30.0% |
| Spokane Valley, WA | 99,275 | 43 | 14.0% |
| Vista, CA | 100,659 | 64 | 28.0% |
| Vacaville, CA | 99,958 | 35 | 30.0% |
Here are the best places to live in California
See the best places to live in Vacaville
Check out the 10 most dangerous cities in California
Most Dangerous States In The US