What is the hottest month in Walnut?

July is the warmest month in Walnut, with an average high of 86.1°F.

What is the coldest month in Walnut?

January is the coldest month in Walnut, with an average low of 9.9°F.

What month does Walnut get the most rain?

June is typically the wettest month in Walnut, with about 5.74 inches of precipitation.

What plant hardiness zone is Walnut in?

Walnut is approximately in USDA plant hardiness Zone 6a, based on the average annual extreme minimum temperature.

Has the climate in Walnut changed recently?

9.3% of Walnut's all-time daily heat records were set in the last decade (since 2015), compared to roughly 5% if records were evenly distributed over time.

Walnut, IA

Climate overview — based on NOAA 1991-2020 normals from ATLANTIC 1 NE, IA US.

Dfa Hot-summer humid continental climate 6a USDA hardiness Zone 6a

Year-round temperatures (°F)

Avg high Avg low

Climate summary

Walnut has an annual average temperature of 49.3°F with about 37.1 inches of precipitation per year and 27.3 inches of snow. The warmest month is July (average high 86.1°F), and the coldest is January (average low 9.9°F). June is typically the wettest month (5.74 in) and January the driest (0.86 in). Snow typically falls from October through April.

Pleasant months

1 / 12

avg high 65–80°F, low ≥ 50°F

Annual swing

54.2°F

warmest to coldest month

Heating need

6,375

HDD/yr

Cooling need

708

CDD/yr

Best time to visit Walnut

Full guide →

Climate change signal

All-time records →

34 of 366 (9.3%) of Walnut'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.

1890s		28
1900s		12
1910s		25
1920s		18
1930s		103
1940s		17
1950s		15
1960s		13
1970s		8
1980s		24
1990s		24
2000s		30
2010s		28
2020s		21

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	31.2°F	9.9°F	20.6°F	0.86 in	5.1 in	6
February	36.1°F	13.7°F	24.9°F	1.14 in	7.9 in	7
March	50.0°F	24.8°F	37.4°F	1.89 in	3.4 in	8
April	62.7°F	35.9°F	49.3°F	3.81 in	0.5 in	12
May	73.1°F	49.3°F	61.2°F	5.43 in	—	14
June	82.8°F	59.8°F	71.3°F	5.74 in	—	12
July	86.1°F	63.5°F	74.8°F	4.40 in	—	10
August	84.4°F	60.6°F	72.5°F	4.44 in	—	9
September	78.2°F	50.8°F	64.5°F	3.35 in	—	9
October	65.0°F	38.1°F	51.5°F	2.93 in	0.7 in	9
November	49.2°F	25.4°F	37.3°F	1.65 in	2.0 in	6
December	36.3°F	15.3°F	25.8°F	1.50 in	7.7 in	7