Decatur, IA

Climate overview — based on NOAA 1991-2020 normals from LAMONI MUNI AP, IA US.

Dfa Hot-summer humid continental climate 7a USDA hardiness Zone 7a

Year-round temperatures (°F)

10° 30° 50° 70° 90° J F M A M J J A S O N D
Avg high Avg low

Climate summary

Decatur has an annual average temperature of 51.6°F with about 37.4 inches of precipitation per year. The warmest month is July (average high 85.4°F), and the coldest is January (average low 15.6°F). May is typically the wettest month (5.14 in) and January the driest (1.04 in).

Pleasant months
2 / 12
avg high 65–80°F, low ≥ 50°F
Annual swing
51.5°F
warmest to coldest month
Heating need
5,655
Cooling need
822

Best time to visit Decatur

Full guide →

Climate change signal

All-time records →

148 of 366 (40.4%) of Decatur'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
15
2000s
118
2010s
152
2020s
81

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 33.1°F 15.6°F 24.3°F 1.04 in 6
February 38.1°F 19.6°F 28.8°F 1.35 in 7
March 50.8°F 30.7°F 40.8°F 2.20 in 10
April 62.5°F 41.4°F 52.0°F 4.25 in 11
May 72.0°F 52.5°F 62.3°F 5.14 in 13
June 81.5°F 62.2°F 71.8°F 4.81 in 12
July 85.4°F 66.2°F 75.8°F 4.11 in 9
August 83.8°F 63.9°F 73.9°F 4.38 in 10
September 76.5°F 55.2°F 65.9°F 3.71 in 9
October 64.0°F 43.3°F 53.6°F 2.82 in 9
November 49.7°F 31.1°F 40.4°F 2.09 in 7
December 37.7°F 20.9°F 29.3°F 1.48 in 7

Climate twins of Decatur

Why these? →

The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).

Frost dates
Last spring / first fall frost
All-time records
Hottest, coldest, wettest
Planting calendar
What to plant, and when

Compare Decatur to another city