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16 lis 2023 · The USDA released their new Plant Hardiness Zone map, which shows significant changes in Illinois’ hardiness zones, reflecting the impact of human-caused climate change. The newest Illinois maps is available here.
View the new 2023 Illinois Hardiness Zone Map. Based on the 1990 USDA Hardiness Zone Map, this interactive version covers the state of Illinois which ranges from USDA Zone 4b to USDA Zone 6b.
The USDA Plant Hardiness Zone Map is the standard by which gardeners and growers can determine which perennial plants are most likely to thrive at a location. The map is based on the average annual extreme minimum winter temperature, displayed as 10-degree F zones and 5-degree F half zones.
Hardiness Zones, also referred to as Growing Zones or Planting zones are defined by the U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS). The zones in this map were created in 2023 using mean extreme climate data covering the period of 1991 to 2020.
Using the 1990 USDA Hardiness Zone classifications, this updated interactive version covers the state of Illinois and was compiled using National Weather Service climate data through 2009 and covering a broader time frame than the 30 year range used in the current USDA map.
30 lis 2023 · The Department of Agriculture has divided the US into 9 zones (with sub-zones). Each zone represents a 10oF spread of how cold the average coldest day of the year is. Far northwestern Illinois is 5a, while far southern Illinois is 7a. The rest of the state falls somewhere in between.
13 lut 2024 · The USDA Hardiness Zone Map has been updated to reflect temperature data collected over the last 30 years. This new map version used GIS technology and input from climate, botanical, and horticulture experts to create hardiness zones on a much finer scale.
