Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
January | 40°F | 70°F | 54°F | 1.6" |
February | 41°F | 71°F | 55°F | 1.4" |
March | 44°F | 75°F | 58°F | 0.8" |
April | 47°F | 78°F | 61°F | 0.4" |
May | 52°F | 82°F | 65°F | 0.3" |
June | 57°F | 89°F | 71°F | 0.0" |
July | 62°F | 94°F | 76°F | 0.1" |
August | 61°F | 96°F | 77°F | 0.0" |
September | 59°F | 94°F | 74°F | 0.1" |
October | 52°F | 86°F | 67°F | 0.3" |
November | 44°F | 78°F | 60°F | 0.4" |
December | 39°F | 69°F | 53°F | 2.0" |
Index | Walnut | California | National |
Air quality index | 89 | 55 | 50 |
Pollution index | 858,652 | 10,473,190 | 2,726,193 |
Measurement | Total |
Days measured | 365 |
Days with good air quality | 42 |
Days with moderate air quality | 178 |
Days w/ poor A.Q. for sensitive groups | 79 |
Days with unhealthy air quality | 58 |
Pollutant | Total |
Arsenic | 0.002% |
Benzene | 0.010% |
Carbon Tetrachloride | 0.000% |
Lead | 0.020% |
Mercury | 0.001% |
City | Population | Air Quality Index | National Avg. |
Cerritos, CA | 49,797 | 72 | 44.0% |
La Habra Heights, CA | 5,406 | 72 | 44.0% |
Norwalk, CA | 106,360 | 72 | 44.0% |
West Whittier-Los Nietos, CA | 27,071 | 72 | 44.0% |
East Whittier, CA | 10,435 | 72 | 44.0% |
Walnut, CA | 30,026 | 89 | 78.0% |
City | Population | Air Quality Index | National Avg. |
North Chicago, IL | 30,023 | 39 | 22.0% |
Rochester, NH | 30,052 | 27 | 46.0% |
Matthews, NC | 30,054 | 49 | 2.0% |
Westchester, FL | 30,058 | 41 | 18.0% |
San Pablo, CA | 29,991 | 40 | 20.0% |
Walnut, CA | 30,026 | 89 | 78.0% |