US Lawn & Growing Season Insights
National analysis of growing seasons, hardiness zones, and lawn climate patterns across all 3,144 US counties. Data from NOAA NCEI 1991-2020 Climate Normals and USDA PHZM.
National Avg Season
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National Avg Temp
54.5°F
Counties Analyzed
0
Key Findings
Growing season length varies dramatically across the United States. leads with an average of days, while averages just days. This -day spread means lawn care strategies must be highly localized.
Nationally, counties average days between the last spring frost and first fall frost. Warmer southern counties often see 250+ day seasons, while northern mountain counties may have fewer than 100 frost-free days — a critical factor when selecting grass species and planning seeding calendars.
State Growing Season Rankings
Average frost-free days by state, computed from all counties with data. Southern and coastal states dominate the top, while northern and mountain states anchor the bottom.
Longest Seasons
Shortest Seasons
Growing Season Distribution
How US counties are distributed across growing season lengths. Most counties fall in the 150-250 day range, with a long tail of short-season counties in the northern mountains and Alaska.
Temperature vs. Growing Season
Each point is a US county. Warmer counties almost always have longer growing seasons, but the relationship is non-linear due to altitude and maritime effects. Bubble size represents extreme heat days.
Hardiness Zone Distribution
Number of counties in each USDA plant hardiness zone. Zones 6a through 8b cover the majority of US counties where lawns are commonly grown.
Longest Growing Seasons
The 10 counties with the longest frost-free periods. These are predominantly southern Florida, Hawaii, and coastal California counties.