Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for Stillwater, OK

Stillwater, OK is in USDA zone 7a across its 5 ZIP codes. The median last spring frost is April 5 and the first fall frost October 30.

Stillwater on the zone map

Outlined: its 4 ZIP code areas · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone7a0 to 5 °F
ZIP codes5
Last frostApr 5
First frostOct 30
Growing season206 days

7a 5 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Stillwater, OK

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 5median — 50% chance of a later frost
Safe for tender plantsApril 21only 10% chance of frost after
First fall frostOctober 30median — 10% chance by Oct 16
Growing season206 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 27 and returns around November 9.

From the NOAA station Stillwater 2 W, OK, elevation 889 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in Stillwater

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 22 – Mar 8
SpinachSow outdoors · Feb 22 – Mar 15
Broccoli, cabbageStart indoors · Jan 25 – Feb 8
Broccoli, cabbageTransplant · Mar 15 – Mar 29
Onion setsPlant outdoors · Mar 8 – Mar 22
PotatoesPlant outdoors · Mar 15 – Mar 29
LettuceSow outdoors · Mar 8 – Mar 22
Carrots, beetsSow outdoors · Mar 15 – Mar 29
TomatoesStart indoors · Feb 8 – Feb 22
TomatoesTransplant · Apr 12 – Apr 26
Peppers, eggplantStart indoors · Jan 25 – Feb 8
Peppers, eggplantTransplant · Apr 19 – May 3
BeansSow outdoors · Apr 12 – Apr 26
Sweet cornSow outdoors · Apr 12 – Apr 26
Cucumbers, squashSow outdoors · Apr 12 – Apr 26
Fall lettuce, spinachSow outdoors · Sep 4 – Sep 18
GarlicPlant cloves · Oct 16 – Nov 20
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 5) and first fall frost (Oct 30) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 74077 came on Feb 14 — 13 days earlier than the 1991–2020 average (Feb 27).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 7a in Oklahoma

511 plants native to the lower 48 states, recorded in Oklahoma, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. Each links to its USDA PLANTS profile.

Trees 59

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °FArizona walnut50 ft · blooms late spring · high shade tolerance · to −33 °Fbald cypress130 ft · blooms mid spring · medium shade tolerance · to −18 °F

Shrubs 90

alderleaf mountain mahogany15 ft · blooms late spring · medium shade tolerance · to −41 °FAmerican beautyberry6 ft · blooms early summer · medium shade tolerance · to −8 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °FAmerican hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °FAmerican plum24 ft · blooms mid spring · high shade tolerance · to −38 °F

Wildflowers & perennials 187

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 153

alkali sacaton3 ft · blooms mid summer · high shade tolerance · to −38 °FAmerican cupscale3 ft · blooms early summer · high shade tolerance · to −18 °FArizona cottontop4 ft · blooms late summer · high shade tolerance · to −13 °FArizona threeawn2 ft · blooms mid summer · high shade tolerance · to −3 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °F

Vines 15

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °FAmerican wisteria50 ft · blooms spring · low shade tolerance · to −3 °Fcatbird grape30 ft · blooms late spring · medium shade tolerance · to −13 °Fcupseed30 ft · blooms late spring · low shade tolerance · to −3 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Stillwater, OK.

Soil in Stillwater, OK

The soil mapped at the center of ZIP 74077 is Renfrow — silt loam, well drained.

TextureSilt loama good balance for most vegetables
pH6.0slightly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2%moderate
Hydrologic groupDwater soaks in very slowly
Farmland classNot prime farmlandUSDA classification

Map unit: Renfrow-Urban land complex, 1 to 5 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 74077; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Stillwater, OK

Summer high94 °Faverage high, July
Winter low26 °Faverage low, January
Hot days76days a year at 90 °F or more
Freezing nights88nights a year at 32 °F or less
Growing degree days5,052base 50 °F — the season’s usable heat
Longest day14 h 37 mindaylight on June 21
Shortest day9 h 42 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation36 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 49 °F, low 26 °F 49°26° JanFebruary: average high 54 °F, low 30 °F 54°30° FebMarch: average high 63 °F, low 38 °F 63°38° MarApril: average high 72 °F, low 47 °F 72°47° AprMay: average high 79 °F, low 58 °F 79°58° MayJune: average high 88 °F, low 67 °F 88°67° JunJuly: average high 94 °F, low 71 °F 94°71° JulAugust: average high 93 °F, low 70 °F 93°70° AugSeptember: average high 85 °F, low 61 °F 85°61° SepOctober: average high 73 °F, low 49 °F 73°49° OctNovember: average high 61 °F, low 37 °F 61°37° NovDecember: average high 51 °F, low 29 °F 51°29° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 1.32 in precipitation 1.3 JanFebruary: 1.56 in precipitation 1.6 FebMarch: 2.75 in precipitation 2.8 MarApril: 4.15 in precipitation 4.2 AprMay: 4.71 in precipitation 4.7 MayJune: 4.64 in precipitation 4.6 JunJuly: 3.42 in precipitation 3.4 JulAugust: 3.66 in precipitation 3.7 AugSeptember: 2.94 in precipitation 2.9 SepOctober: 2.94 in precipitation 2.9 OctNovember: 2.28 in precipitation 2.3 NovDecember: 1.67 in precipitation 1.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Stillwater 2 W, OK (within 1 mile); precipitation: Stillwater 2 W, OK (within 1 mile). Daylight is calculated from latitude.

ZIP codes in Stillwater

740747a
0 to 5 °F
740757a
0 to 5 °F
740767a
0 to 5 °F
740777a
0 to 5 °F
740787a
0 to 5 °F

Oklahoma planting zones →

Questions about Stillwater

What planting zone is Stillwater, OK?

Stillwater, OK is in USDA hardiness zone 7a on the 2023 map (7a: 0 to 5 °F).

When is the last frost in Stillwater, OK?

The median last spring frost is April 5 and the median first fall frost is October 30 (NOAA 1991–2020 normals, Stillwater 2 W station).

When can I plant a garden in Stillwater, OK?

Cool-season crops like peas and spinach go in around Feb 22 – Mar 15; tomatoes, peppers, beans and squash after about Apr 12, once frost risk has passed.

What kind of onions grow in Stillwater, OK?

Intermediate onions: the longest day is 14 h 37 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

How much rain and snow does Stillwater, OK get?

About 36 inches of precipitation a year (NOAA 1991–2020 normals).