Weather in Iowa

Calculated from weather data of Decorah Municipal Airport (KDEH) between 2020 and 2024.

Maximum temperatures (°F)

Month	Average	2024	2023	2022	2021	2020
January	26.0	26.0	29.0	23.0	28.0	29.0
February	31.0	46.0	34.0	28.0	18.0	30.0
March	44.0	50.0	41.0	43.0	49.0	44.0
April	56.0	57.0	58.0	51.0	58.0	56.0
May	69.0		74.0	70.0	67.0	67.0
June	79.0		80.0	79.0	83.0	80.0
July	81.0		80.0	81.0	81.0	83.0
August	78.0		82.0	77.0	80.0	80.0
September	74.0		76.0	72.0	74.0	69.0
October	58.0		61.0	61.0	63.0	53.0
November	44.0		48.0	44.0	46.0	51.0
December	35.0		40.0	32.0	37.0	34.0
Average	55.0	45.0	59.0	55.0	57.0	56.0

Average highest temperature per day

The maximum temperature is typically observed some hours after noon.

Minimum temperatures (°F)

Month	Average	2024	2023	2022	2021	2020
January	14.0	17	18	4	18	17
February	15.0	27	18	9	6	14
March	28.0	31	27	28	33	32
April	37.0	40	38	35	40	35
May	50.0		51	50	50	49
June	60.0		60	56	63	61
July	63.0		60	64	64	65
August	61.0		62	63	62	61
September	54.0		57	54	43	53
October	41.0		43	40	46	37
November	29.0		32	30	30	33
December	22.0		30	21	22	20
Average	38.0	29.0	41.0	38.0	40.0	40.0

Average lowest temperature per day

The minimum temperature is typically observed just before sunrise.

Cold and hot days

Number of days	2024	2023	2022	2021	2020
86 °F or warmer	0	14	10	17	13
77 °F or warmer	1	93	68	76	75
68 °F or warmer	6	153	129	140	136
32 °F or colder	63	118	123	119	135

Precipitation (%)

Month	Average	2024	2023	2022	2021	2020
January	9.3	11	12	7	6	9
February	7.5	0	9	8	9	5
March	5.9	7	7	8	5	6
April	6.0	11	4	4	2	6
May	3.7		4	4	3	4
June	3.0		2	2	2	5
July	1.6		1	4	2	1
August	2.3		1	5	2	2
September	2.7		2	2	1	7
October	4.7		5	2	5	4
November	4.9		1	17	2	4
December	6.4		5	15	4	3
Average	5.0	7.6	4.1	5.6	3.3	4.5

Precipitation during daylight period

Percentage of observations with observed rain, drizzle, snow or hail. Only observations between sunrise and sunset are taken into account.

Wind speed (miles per hour)

Month	Average	2024	2023	2022	2021	2020
January	7.9	7	7	9	7	8
February	8.7	9	9	10	8	8
March	9.5	10	9	10	10	9
April	10.3	11	11	12	9	10
May	8.1		8	9	8	9
June	6.3		5	4	6	7
July	5.5		5	6	6	5
August	5.7		6	5	6	7
September	6.8		6	7	5	8
October	8.1		9	8	7	9
November	8.6		8	10	10	9
December	7.8		8	8	8	7
Average	7.9	9.3	7.4	8.0	7.5	8.0

Average wind speed

Excluding wind gusts. Only observations between sunrise and sunset are taken into account.

Prevailing wind direction

Month	2024	2023	2022	2021	2020
January	NW	NW	W	N	W
February	W	NW	NW	NW	NW
March	NW	N	NW	SE	W
April	NW	W	SW	NW	NW
May		E	SE	S	NE
June		NE	S	SW	SE
July		NW	S	NE	SW
August		NW	S	S	W
September		SE	W	NW	SW
October		NW	W	NE	NW
November		W	SW	W	SW
December		W	SE	SW	W

Prevailing wind direction

Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.

Iowa weather Q&A

What is the warmest month in Iowa?

The warmest month is July with an average temperature of 81 °F over the past years.

What is the coldest month in Iowa?

The coldest month is January with an average daytime temperature of 26 °F in the past few years.

Which month is the wettest in Iowa?

Chance of precipitation is the highest in January with a probability of around 9.3 %.

Which month is the driest in Iowa?

The least rainfall and snow can be expected in July. The probability is about 1.6 %.