| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 14°F | 37°F | 24°F | 0.6" |
| February | 16°F | 41°F | 27°F | 0.9" |
| March | 29°F | 56°F | 41°F | 1.5" |
| April | 40°F | 67°F | 53°F | 3.8" |
| May | 50°F | 77°F | 63°F | 5.2" |
| June | 62°F | 87°F | 74°F | 4.9" |
| July | 66°F | 91°F | 78°F | 3.1" |
| August | 64°F | 88°F | 75°F | 6.1" |
| September | 55°F | 82°F | 67°F | 3.7" |
| October | 42°F | 69°F | 54°F | 3.0" |
| November | 29°F | 55°F | 41°F | 1.0" |
| December | 17°F | 39°F | 27°F | 1.7" |
| Index | Griswold | Iowa | National |
| Air quality index | 40 | 39 | 42 |
| Pollution index | 338,773 | 1,154,535 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 283 |
| Days with moderate air quality | 82 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Cumberland, IA | 252 | 40 | 20.0% |
| Atlantic, IA | 6,600 | 40 | 20.0% |
| Elliott, IA | 539 | 40 | 20.0% |
| Lewis, IA | 513 | 40 | 20.0% |
| Hancock, IA | 263 | 40 | 20.0% |
| Griswold, IA | 1,179 | 40 | 20.0% |
| City | Population | Air Quality Index | National Avg. |
| Pomona Park, FL | 1,179 | 17 | 66.0% |
| Kellyville, OK | 1,179 | 45 | 10.0% |
| Oceana, WV | 1,179 | 295 | 490.0% |
| Vauxhall, AB | 1,179 | n/a | |
| Duchess, AB | 1,179 | n/a | |
| Griswold, IA | 1,179 | 40 | 20.0% |
Here are the best places to live in Iowa
Check out the 10 most dangerous cities in Iowa
Safest Cities In The US
See the best places to live in Griswold