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

Planting zone for 97121 — Hammond, OR

ZIP code 97121 (Hammond, Clatsop County) is in USDA zone 9a: the coldest winter night averages 20 to 25 °F. The median last spring frost is March 26 and the first fall frost November 11.

Where ZIP 97121 is

Outlined: the ZIP code area · 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.

Zone9a20 to 25 °F
Coldest night−6.7 to −3.9 °C
Last frostMar 26
First frostNov 11
2012 zone9a

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 9a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Hammond, OR…

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 Hammond, OR

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostMarch 26median — 50% chance of a later frost
Safe for tender plantsApril 18only 10% chance of frost after
First fall frostNovember 11median — 10% chance by Oct 22
Growing season232 daysfrost-free, median

A hard freeze (28 °F) usually ends around February 18 and returns around December 5.

From the NOAA station Astoria Regional Airport, OR — 6 miles away, elevation 10 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 97121

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Feb 12 – Feb 26
SpinachSow outdoors · Feb 12 – Mar 5
Broccoli, cabbageStart indoors · Jan 15 – Jan 29
Broccoli, cabbageTransplant · Mar 5 – Mar 19
Onion setsPlant outdoors · Feb 26 – Mar 12
PotatoesPlant outdoors · Mar 5 – Mar 19
LettuceSow outdoors · Feb 26 – Mar 12
Carrots, beetsSow outdoors · Mar 5 – Mar 19
TomatoesStart indoors · Jan 29 – Feb 12
TomatoesTransplant · Apr 2 – Apr 16
Peppers, eggplantStart indoors · Jan 15 – Jan 29
Peppers, eggplantTransplant · Apr 9 – Apr 23
BeansSow outdoors · Apr 2 – Apr 16
Sweet cornSow outdoors · Apr 2 – Apr 16
Cucumbers, squashSow outdoors · Apr 2 – Apr 16
Fall lettuce, spinachSow outdoors · Sep 16 – Sep 30
GarlicPlant cloves · Oct 28 – Dec 2
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 26) and first fall frost (Nov 11) 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 97121 came on Feb 3 — 6 days earlier than the 1991–2020 average (Feb 9).

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).

Soil in Hammond, OR

The soil mapped at the center of ZIP 97121 is Coquille — silt loam, very poorly drained.

TextureSilt loama good balance for most vegetables
pH6.5neutral; most vegetables like 6.0–7.0
DrainageVery poorly drainedconsider raised beds
Organic matter7%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classNot prime farmlandUSDA classification

Map unit: Coquille-Clatsop complex, 0 to 1 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 97121; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Hammond, OR

Summer high69 °Faverage high, August
Winter low37 °Faverage low, February
Hot days1days a year at 90 °F or more
Freezing nights29nights a year at 32 °F or less
Growing degree days1,494base 50 °F — the season’s usable heat
Longest day15 h 47 mindaylight on June 21
Shortest day8 h 37 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation70.3 inper year, rain and melted snow

Average high and low, by month

30°40°50°60°70°80°32 °FJanuary: average high 49 °F, low 38 °F 49°38° JanFebruary: average high 51 °F, low 37 °F 51°37° FebMarch: average high 53 °F, low 39 °F 53°39° MarApril: average high 56 °F, low 42 °F 56°42° AprMay: average high 61 °F, low 46 °F 61°46° MayJune: average high 64 °F, low 51 °F 64°51° JunJuly: average high 67 °F, low 54 °F 67°54° JulAugust: average high 69 °F, low 54 °F 69°54° AugSeptember: average high 68 °F, low 51 °F 68°51° SepOctober: average high 61 °F, low 45 °F 61°45° OctNovember: average high 54 °F, low 40 °F 54°40° NovDecember: average high 49 °F, low 38 °F 49°38° Dec

Precipitation by month inches

0″2″4″6″8″10″12″January: 10.59 in precipitation 10.6 JanFebruary: 7.18 in precipitation 7.2 FebMarch: 7.90 in precipitation 7.9 MarApril: 5.80 in precipitation 5.8 AprMay: 3.40 in precipitation 3.4 MayJune: 2.30 in precipitation 2.3 JunJuly: 0.83 in precipitation 0.8 JulAugust: 1.12 in precipitation 1.1 AugSeptember: 2.67 in precipitation 2.7 SepOctober: 6.74 in precipitation 6.7 OctNovember: 11.05 in precipitation 11.1 NovDecember: 10.68 in precipitation 10.7 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Astoria Regional Airport, OR (6 mi away); precipitation: Astoria Regional Airport, OR (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

4 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

986148b
Chinook, WA · 6 mi
971469a
Warrenton, OR · 6 mi
986449a
Seaview, WA · 9 mi
986249a
Ilwaco, WA · 9 mi
986319a
Long Beach, WA · 13 mi
971038b
Astoria, OR · 14 mi
986388b
Naselle, WA · 17 mi
986438b
Rosburg, WA · 17 mi

Oregon planting zones →

Questions about 97121

What planting zone is ZIP code 97121?

ZIP code 97121 (Hammond, OR) is in USDA hardiness zone 9a on the 2023 map: the coldest night of an average winter reaches 20 to 25 °F (−6.7 to −3.9 °C).

When is the last frost in Hammond, OR?

The median last spring frost (32 °F) near 97121 is March 26; after April 18 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Astoria Regional Airport station.

When is the first frost in Hammond, OR?

The median first fall frost near 97121 is November 11, giving a median frost-free growing season of 232 days.

When should I plant tomatoes in 97121?

Start tomato seeds indoors around Jan 29 – Feb 12 and set transplants outside around Apr 2 – Apr 16, one to three weeks after the median last frost.

How much rain and snow does 97121 get?

About 70.3 inches of precipitation a year (NOAA 1991–2020 normals, Astoria Regional Airport station).

How hot do summers get in Hammond, OR?

The average high peaks at 69 °F in August, with about 1 days a year at 90 °F or more.

What kind of soil does 97121 have?

The USDA soil survey maps Coquille at the center of ZIP 97121: silt loam, very poorly drained, pH about 6.5 (neutral).

Did spring come early in Hammond, OR in 2026?

Spring leaf-out near 97121 came on Feb 3 in 2026, 6 days earlier than the 1991–2020 average (Feb 9), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Hammond, OR?

Long-day onions: the longest day near 97121 is 15 h 47 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).