Johnston, IA
Climate overview — based on NOAA 1991-2020 normals from DES MOINES WSFO-JOHNSTON, IA US.
Year-round temperatures (°F)
Climate summary
Johnston has an annual average temperature of 50.3°F with about 36.2 inches of precipitation per year and 38 inches of snow. The warmest month is July (average high 84.7°F), and the coldest is January (average low 13.1°F). June is typically the wettest month (5.35 in) and January the driest (1.01 in). Snow typically falls from October through May.
Best time to visit Johnston
Full guide →Climate change signal
All-time records →138 of 366 (37.7%) of Johnston's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.
| 1990s | 43 | |
| 2000s | 127 | |
| 2010s | 108 | |
| 2020s | 88 |
Bars: number of all-time daily heat records still standing that were set in each decade.
Monthly averages
| Month | Avg High | Avg Low | Avg Temp | Precipitation | Snow | Rainy days |
|---|---|---|---|---|---|---|
| January | 30.0°F | 13.1°F | 21.5°F | 1.01 in | 9.7 in | 8 |
| February | 35.1°F | 17.3°F | 26.2°F | 1.25 in | 10.5 in | 8 |
| March | 48.6°F | 28.8°F | 38.7°F | 2.15 in | 5.0 in | 9 |
| April | 61.5°F | 40.1°F | 50.8°F | 4.00 in | 1.6 in | 11 |
| May | 71.8°F | 51.8°F | 61.8°F | 4.84 in | 0.2 in | 13 |
| June | 80.9°F | 62.0°F | 71.5°F | 5.35 in | — | 12 |
| July | 84.7°F | 65.6°F | 75.2°F | 4.27 in | — | 9 |
| August | 82.9°F | 63.6°F | 73.2°F | 3.97 in | — | 10 |
| September | 76.2°F | 55.1°F | 65.6°F | 3.40 in | — | 8 |
| October | 63.1°F | 42.5°F | 52.8°F | 2.51 in | 0.5 in | 9 |
| November | 47.7°F | 29.9°F | 38.8°F | 1.95 in | 2.2 in | 7 |
| December | 35.2°F | 19.0°F | 27.1°F | 1.46 in | 8.3 in | 8 |
Climate twins of Johnston
Why these? →The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).