When to Plant Grass Seed in Hawaii

Warm-season lawns dominate Hawaii, and warm-season seed wants 2-inch soil at 65°F and rising with a full growing season ahead. The dates below are typical crossings from in-state monitoring stations; your city page tracks the live reading.

Best Time to Plant Grass Seed in Hawaii

Warm-season · planting window

March 16

January 19 (warmest parts) to June 12 (coolest)

For warm-season lawns (bermuda, zoysia), the best time to plant grass seed in Hawaii is once 2-inch soil reaches 65°F and keeps rising, with a full growing season ahead; soil that warm arrives early in the year here. Soil stays above 65°F until about November 10, but seed sown after the summer peak cannot establish before dormancy, so the practical window closes by midsummer; the month-by-month table below shows where that falls.

Soil across Hawaii stays above the cool-season minimum of 50°F year-round, so the warm-season band is the constraint that matters. For a green lawn through winter, some homeowners overseed with ryegrass; the winter overseeding guide covers that timing.

Timing varies within Hawaii: your city page tracks the local window from its nearest station: see when to plant in Honolulu, when to plant in Kapolei or when to plant in Hilo. Today's statewide reading is on the Hawaii soil temperature page.

Typical dates are computed from historical 2-inch soil temperature averages at 6 monitoring stations in Hawaii; your own window depends on your nearest station's readings.

Best Time to Plant Grass Seed in Hawaii: Month by Month

Typical 2-inch soil temperature by month across Hawaii, the median of 6 in-state stations with multi-year records, with the seeding verdict for each grass family. Confirm against the current reading on your city page before you put seed down.

Month	Typical 2" soil temp	Cool-season seeding	Warm-season seeding
January	65°F	Good; fall is better	Prime window
February	65°F	Good; fall is better	Prime window
March	67°F	Risky; heat ahead	Prime window
April	67°F	Risky; heat ahead	Prime window
May	67°F	Risky; heat ahead	Prime window
June	70°F	Risky; heat ahead	Prime window
July	72°F	Risky; heat ahead	Prime window
August	72°F	Soon; still cooling	Too late this year
September	70°F	Soon; still cooling	Too late this year
October	69°F	Soon; still cooling	Too late this year
November	67°F	Soon; still cooling	Too late this year
December	65°F	Prime window	Too late this year