The USDA has updated the geographic zones that help gardeners select plants that are suitable for their regions. Learn why the map changed—and whether your area was affected.

The new map, created by USDA's Agricultural Research Service and Oregon State University, is based on 30 years of data from 13,412 weather stations, almost twice as many as the old map.

Heat domes, atmospheric rivers, bomb cyclones, and polar vortex—you’re not crazy, the weather is. And last week, the USDA confirmed it by releasing an updated climate zone map for 2023. For ...

The map reflects the “average lowest winter temperature” over a 30-year period at specific locations in each of the zones, according to the USDA. Overall, that average for the country was 2.5 ...

In the previous map, most of northern Indiana, including Whiley County, was predominantly in Zone 5b. “Average” is the operative word on this map, based on recent 20-year temperature measurements.

For example, Seattle, Washington, and the city of Austin, Texas, are both in the USDA hardiness zone 9a because the map is a measure of the coldest temperature a plant can handle.

One of the major changes in this year’s edition of the hardiness map is the zone boundaries. The USDA states that the new zones are generally about one-quarter-zone warmer than reported in 2012 ...

For the first time since 2012, a new Plant Hardiness Zone Map has been released by the U.S. Department of Agriculture. The map, released Nov. 15, 2023, is a tool used by gardeners and growers ...

Compared to the 2012 map, the 2023 version shows that roughly half of the country shifted to the next warmer half zone, and the other half of U.S. remained in the same half zone.. According to the ...

The USDA map divides the United States into 13 plant hardiness zones based on each location’s annual extreme minimum temperature. Each zone spans a 10-degree temperature range.

The USDA Plant Hardiness Zone Map uses weather data to map average annual extreme minimum temperatures (winter lows) over a recent 20-year period. The most recent release covers weather data from 1991 ...

According to the USDA, the map is also based on 30-year averages of the lowest annual winter temperatures at the specific locations, and split into 10-degree and 5-degree zones and integrates data ...