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ZIP 93721 planting calendar

When to plant watermelon in Fresno, CA - Zone 9b

In ZIP 93721, plant watermelon around Mar 6; this uses the Fresno frost station, USDA zone 9b, and watermelon timing rules.

Your Fresno calendar has a 278-day estimated frost-free season. This estimate uses the representative Fresno frost station, USDA zone 9b, and watermelon timing rules.

Source: fresno-yosemite frost station, USDA zone 9b, last updated 2026-06-28. Verify locally before planting high-value crops because microclimates, current weather, and yard exposure can move the safe date.

Reviewed by GrowZone Editorial. Calculated from the fresno-yosemite frost station and USDA zone 9b, last updated 2026-06-28.

In the Fresno area, watermelon timing follows the Fresno frost window, so the local ZIP date can differ from a broad zone-only calendar.

USDA zone 9b Fresno frost station University of California Agriculture and Natural Resources Updated 2026-06-28
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Answer first

When to start watermelon seeds indoors in Fresno

In ZIP 93721, start watermelon seeds indoors around Jan 30, about 21 days before the Feb 20 last-frost estimate.

Start watermelon seeds indoors in Fresno around Jan 30, about 21 days before the Feb 20 last-frost estimate.

Seed starting schedule

Watermelon dates for Fresno, CA

StepDateHow to use it
Start IndoorsJanuary 30, 2026Start seeds under lights or in a bright indoor seed-starting space.
Transplant OutdoorsMarch 6, 2026Move hardened-off seedlings outside after the frost-risk window.
Direct SowMarch 6, 2026Sow seed outside when the crop and soil can handle the window.

Last frost

When is the last frost in Fresno?

Fresno (ZIP 93721) has an average last spring frost around Feb 20.

First frost

When is the first frost in Fresno?

The average first fall frost is around Nov 25, giving about 278 frost-free days.

Season map

Watermelon windows by month

JanFebMarAprMayJunJulAugSepOctNovDec
Start indoors
Jan 30
Direct sow
Mar 6
Transplant
Mar 6
Harvest
Jun 4
Frost watch
Aug 27

Reminder workflow

Every date has a next action

Start watermelon indoorsJan 30
Last frost windowFeb 20
Direct sow watermelonMar 6
Transplant watermelonMar 6
First watermelon harvest windowJun 4
Last watermelon sowing targetAug 27
SignalValueWhy it matters
Last frost estimateFebruary 20, 2026Warm-season transplant risk starts falling after this window.
First frost estimateNovember 25, 2026Fall planting counts backward from this date.
Season length278 daysLonger seasons can support succession crops.
Spacing36-60 inAirflow and root space affect yield.
Soil temperature70 F+Seeds and transplants stall in cold soil.

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Local data

Why this date changes by ZIP

Fresno frost history and USDA zone 9b shift the safe planting window. GrowZone uses a local representative station instead of one national rule.

University of California Agriculture and Natural Resources is the kind of local source to verify against when a crop is expensive, weather is unusual, or your yard has a cold pocket.

Crop note

Watermelon timing notes

Wait for warm soil; watermelon stalls when nights stay cool. Watermelon prefers full sun, 36-60 in spacing, and soil near 70 F+.

For fall, count backward from Nov 25. A conservative last sowing target is around Aug 27.