What is the hottest month in Henderson?

July is the warmest month in Henderson, with an average high of 84.0°F.

What is the coldest month in Henderson?

January is the coldest month in Henderson, with an average low of 13.8°F.

What month does Henderson get the most rain?

May is typically the wettest month in Henderson, with about 5.27 inches of precipitation.

What plant hardiness zone is Henderson in?

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

Has the climate in Henderson changed recently?

10.4% of Henderson'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.

Henderson, IL

Climate overview — based on NOAA 1991-2020 normals from GALESBURG, IL US.

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

Year-round temperatures (°F)

Avg high Avg low

Climate summary

Henderson has an annual average temperature of 50.2°F with about 39 inches of precipitation per year and 25.9 inches of snow. The warmest month is July (average high 84.0°F), and the coldest is January (average low 13.8°F). May is typically the wettest month (5.27 in) and January the driest (1.69 in). Snow typically falls from November through April.

Pleasant months

2 / 12

avg high 65–80°F, low ≥ 50°F

Annual swing

52.8°F

warmest to coldest month

Heating need

6,063

HDD/yr

Cooling need

738

CDD/yr

Best time to visit Henderson

Full guide →

Climate change signal

All-time records →

38 of 366 (10.4%) of Henderson'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		16
1900s		33
1920s		0
1930s		29
1940s		31
1950s		49
1960s		31
1970s		24
1980s		38
1990s		21
2000s		35
2010s		37
2020s		22

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	13.8°F	21.9°F	1.69 in	9.0 in	8
February	34.7°F	17.3°F	26.0°F	1.87 in	6.6 in	7
March	48.0°F	28.1°F	38.0°F	2.39 in	2.3 in	9
April	61.3°F	39.9°F	50.6°F	3.83 in	0.4 in	11
May	72.0°F	51.7°F	61.8°F	5.27 in	—	12
June	81.2°F	62.0°F	71.6°F	4.58 in	—	10
July	84.0°F	65.4°F	74.7°F	4.04 in	—	8
August	82.3°F	63.4°F	72.8°F	3.89 in	—	9
September	76.2°F	54.7°F	65.5°F	3.85 in	—	7
October	63.0°F	42.5°F	52.8°F	2.82 in	—	9
November	48.0°F	29.9°F	39.0°F	2.60 in	1.7 in	8
December	35.4°F	20.2°F	27.8°F	2.14 in	5.9 in	8