Plant Hardiness Zones for Colorado
There are many micro climates in Colorado and areas that are relatively close to one another may have different weather patterns, temperatures and hardiness zone ratings.
Tempuratures (Fahrenheit)
-40 to- 35
-35 to -30
-30 to -25
-25 to -20
-20 to -15
-15 to -10
-10 to -5
-5 to 0
-0 to 5
USDA Hardiness Zones
3a
3b
4a
4b
5a
5b
6a
6b
7a
The plant hardiness zone for Boulder is typically 5 with some “hotspots” being in zone 6b and 7a. Hardiness zones for Colorado are (revised in 2012 due to changes in climate temperatures):
• The highest mountain areas 10,000+ are zone 3a-3b.
• Mountain and foothills area zones are 4a and 5a.
• Much of the populated front range is rated as zone 5a-5b.
• Warmest areas in Colorado are zones 5b-6b.
• “Hotspots” such as Denver, Ft. Collins and parts of the plains are zone 6b-7a.