What USDA hardiness zone is Coos County, Oregon?

Coos County, Oregon spans USDA hardiness zones 9a to 9b. 88% of its ZIP codes are zone 9a, so there is no single zone for the county.

When is the last spring frost in Coos County, Oregon?

The median last spring freeze runs February 21 – March 28 across the 5 NOAA weather stations serving Coos County, Oregon, from NOAA 1991-2020 Climate Normals. Half of years freeze later than the median.

Oregon

Planting zones in Coos County, Oregon

This county spans USDA zones 9a to 9b, so there is no single zone for Coos County and anyone who gives you one is rounding. 88% of its ZIP codes are zone 9a; the rest are not.

USDA zones 9a–9b 2 zones across 8 ZIP codes

ZIP codes 8 8 have a NOAA station within range

Weather stations 5 NOAA 1991–2020 normals, across 1,596 sq mi

Your ZIP code

Get the exact answer for your address

Everything above describes Coos County, Oregon as a whole. Hardiness zones and freeze dates are published per ZIP code, so yours is exact — enter it and this page will tell you your zone, which NOAA station it comes from and how far away that station is.

Coos County does not have one planting answer

Its own weather stations disagree about 15 of the 32 crops in this table right now, so any single list would be wrong for part of the county. That is not a gap in the data — it is what the data says.

Shortest season: 225 days
COQUILLE CITY, OR US (USC00351836)
Longest season: 294 days
NORTH BEND RGNL AP, OR US (USW00024284)

69 days of growing season separate those two stations, and both serve ZIP codes in Coos County. The ZIP lookup above answers for one address instead of averaging a place that has no average.

Why the hardiness zone does not settle this

A USDA zone is a winter-minimum statistic. It was never a growing-season one, and it does not behave like one: within a single zone the growing season runs a median 54 days wider at the 10th–90th percentile, and annual growing degree days vary by 2.02×.

The zones also overlap rather than stack — 30% of zone 6b freezes before the median zone 6a station. The zone tells you what survives your winter; the station tells you what finishes before your autumn.

The whole dataset behind that →

All 5 stations agreeAt least one station

Every one of the 5 NOAA stations serving this county counts March 28 – November 6 as growing season (223 days). Widening to any single station gives February 21 – December 9 (291 days).

That is a 68-day difference inside one county — which is why this page gives ranges rather than a single planting date. The ZIP lookup above resolves it to one station.

Which zone you are in depends where you are

Coos County covers 2 hardiness zones. A guide that gives the county one zone has picked whichever is largest and rounded everyone else into it — fine for the 88% in zone 9a and wrong for the other 12%. Here is the actual split.

Zone	ZIP codes	Share
9a	7	88%
9b	1	13%

Zones are published per ZIP code, so yours is exact even though the county's is not. The hardiness tool will tell you which one you are in.

Your freeze dates

Last spring freeze February 21 – March 28

First fall freeze November 6 – December 9

Across the 5 NOAA stations serving this county. These are medians — half of years freeze later than the date shown — so treat the later end of each range as the cautious one.

The growing season runs 225–294 days depending which station you are nearest, as published by NOAA rather than computed from the dates above. Summer highs average 65.6–77.2 °F in June–August. Summer rain over the same months runs 1.9–2.3" across those 4 stations, against the rough inch a week — about 13 inches over the same 92 days — that a vegetable garden is usually reckoned to want. The middle station covers about 18% of it, so a summer garden here is watered rather than rained on. The inches are NOAA's published normals; the inch a week is a rule of thumb, and it takes no account of a 69 °F summer afternoon drying the soil faster than a cool one.

Every ZIP code in Coos County

Zones are published per ZIP code, not per county, so this is the exact answer rather than the county's average. The station column is the nearest one to that ZIP code's centroid and how far away it is — the same figure the tools use, shown here so you can see which ZIP codes are well covered and which are reaching.

ZIP code	USDA zone	Nearest NOAA station	Distance
97411	9b	Bandon 2 Nne, OR	11.0 km
97414	9a	Powers, OR	11.3 km
97420	9a	North Bend Rgnl AP, OR	13.4 km
97423	9a	Coquille City, OR	2.3 km
97449	9a	Winchester Bay Coast Grd, OR	17.2 km
97458	9a	Powers, OR	18.5 km
97459	9a	North Bend Rgnl AP, OR	9.3 km
97466	9a	Powers, OR	4.6 km

ZIP-code positions are area centroids, so a large rural ZIP code's listed distance is measured from the middle of its area rather than from any particular address in it.

When to start seeds in Coos County

Every date below is anchored on the last spring freeze at each station and reported as a range across all 5 of them, because no one station speaks for the county.

Crop	Job	When	Offset
🧅 Green Onions	Start indoors	December 27 – January 31	8 wk before
🌶️ Peppers	Start indoors	December 27 – January 31	8 wk before
🥦 Broccoli	Start indoors	January 10 – February 14	6 wk before
🥬 Cabbage	Start indoors	January 10 – February 14	6 wk before
🥬 Collards	Start indoors	January 10 – February 14	6 wk before
🥬 Kale	Start indoors	January 10 – February 14	6 wk before
🥬 Leaf Lettuce	Start indoors	January 10 – February 14	6 wk before
🫛 Peas	Direct sow	January 10 – February 14	6 wk before
🥬 Spinach	Direct sow	January 10 – February 14	6 wk before
🍠 Sweet Potato	Start indoors	January 10 – February 14	6 wk before
🍅 Tomatoes	Start indoors	January 10 – February 14	6 wk before
🥬 Bok Choy	Start indoors	January 17 – February 21	5 wk before
🥬 Kohlrabi	Start indoors	January 17 – February 21	5 wk before
🥬 Swiss Chard	Start indoors	January 17 – February 21	5 wk before
🥬 Arugula	Direct sow	January 24 – February 28	4 wk before
🥬 Baby Salad Greens	Direct sow	January 24 – February 28	4 wk before
🥕 Beets	Direct sow	January 24 – February 28	4 wk before
🧅 Green Onions	Direct sow	January 24 – February 28	4 wk before
🥬 Mustard Greens	Direct sow	January 24 – February 28	4 wk before
🌶️ Okra	Start indoors	January 24 – February 28	4 wk before
🌱 Radishes	Direct sow	January 24 – February 28	4 wk before
🥔 Turnips	Direct sow	January 24 – February 28	4 wk before
🥬 Cabbage	Set out	January 31 – March 7	3 wk before
🥕 Carrots	Direct sow	January 31 – March 7	3 wk before
🥬 Collards	Direct sow	January 31 – March 7	3 wk before
🥬 Collards	Set out	January 31 – March 7	3 wk before
🥒 Cucumbers	Start indoors	January 31 – March 7	3 wk before
🧅 Green Onions	Set out	January 31 – March 7	3 wk before
🥬 Kale	Direct sow	January 31 – March 7	3 wk before
🥬 Kale	Set out	January 31 – March 7	3 wk before
🥬 Kohlrabi	Direct sow	January 31 – March 7	3 wk before
🥬 Kohlrabi	Set out	January 31 – March 7	3 wk before
🥬 Leaf Lettuce	Direct sow	January 31 – March 7	3 wk before
🎃 Pumpkins	Start indoors	January 31 – March 7	3 wk before
🎃 Summer Squash	Start indoors	January 31 – March 7	3 wk before
🎃 Winter Squash	Start indoors	January 31 – March 7	3 wk before
🥒 Zucchini	Start indoors	January 31 – March 7	3 wk before
🥬 Bok Choy	Direct sow	February 7 – March 14	2 wk before
🥬 Bok Choy	Set out	February 7 – March 14	2 wk before
🥦 Broccoli	Set out	February 7 – March 14	2 wk before
🌿 Cilantro	Direct sow	February 7 – March 14	2 wk before
🥬 Leaf Lettuce	Set out	February 7 – March 14	2 wk before
🥬 Swiss Chard	Direct sow	February 7 – March 14	2 wk before
🥬 Swiss Chard	Set out	February 7 – March 14	2 wk before
🌿 Dill	Direct sow	February 14 – March 21	1 wk before
🫘 Bush Beans	Direct sow	February 28 – April 4	1 wk after
🥒 Cucumbers	Set out	February 28 – April 4	1 wk after
🎃 Pumpkins	Direct sow	February 28 – April 4	1 wk after
🎃 Pumpkins	Set out	February 28 – April 4	1 wk after
🎃 Summer Squash	Direct sow	February 28 – April 4	1 wk after
🎃 Summer Squash	Set out	February 28 – April 4	1 wk after
🌽 Sweet Corn	Direct sow	February 28 – April 4	1 wk after
🍅 Tomatoes	Set out	February 28 – April 4	1 wk after
🎃 Winter Squash	Direct sow	February 28 – April 4	1 wk after
🎃 Winter Squash	Set out	February 28 – April 4	1 wk after
🥒 Zucchini	Direct sow	February 28 – April 4	1 wk after
🥒 Zucchini	Set out	February 28 – April 4	1 wk after
🥒 Cucumbers	Direct sow	March 7 – April 11	2 wk after
🌶️ Okra	Direct sow	March 7 – April 11	2 wk after
🌶️ Okra	Set out	March 7 – April 11	2 wk after
🌶️ Peppers	Set out	March 7 – April 11	2 wk after
🫘 Southern Peas	Direct sow	March 7 – April 11	2 wk after
🍠 Sweet Potato	Set out	March 7 – April 11	2 wk after

Offsets are published guidance; the dates they land on are computed from measured NOAA normals. The seed-starting tool does this for your own ZIP code and counts the days.

What survives the winter changes across Coos County

Zone 9a carries 46 of 74 perennial edibles; zone 9b carries 40. The best number is not always the warmest zone — the count peaks in the middle and falls both ways, because the warm end loses plants to insufficient winter chill and summer heat, not to cold.

Hardiness ranges are a judgement, published by growers rather than measured; the zone they are compared against is measured. On a warm-end verdict, check with your local extension service — a coastal zone 8 and an inland zone 8 are not the same summer.

At least one station here freezes across the new year, which puts the two ends of a spread on opposite sides of the calendar. Drawing it would produce a bar spanning almost the whole year and meaning nothing, so none is drawn.

The 5 stations behind these numbers

All 5 NOAA stations whose normals this page quotes, spanning about 88 km north to south. Every one is named with its identifier in the station list below — this page does not single one out, because no one station speaks for a whole county.

A relative sketch, not a map with a projection: longitude is adjusted for latitude so the shape is not stretched, and there is no basemap. For the one station nearest a specific address, with its real distance, use the ZIP lookup above.

These are the stations this county's ZIP codes actually cite as nearest — not a claim that each one sits inside its boundary, since a rural ZIP legitimately reaches over it. Every figure above comes from them, and each is named so you can check it.

Station	NOAA ID	Last spring freeze	First fall freeze	Season
Bandon 2 Nne, OR	USC00350471	March 9	November 27	260 days
Coquille City, OR	USC00351836	March 28	November 6	225 days
North Bend Rgnl AP, OR	USW00024284	February 21	December 9	294 days
Powers, OR	USC00356820	March 21	November 14	241 days
Winchester Bay Coast Grd, OR	USC00353193	March 25	November 24	249 days

These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.

Your own ZIP

Work out your own dates

This page describes a whole county. Every tool below answers for one ZIP code, which is the grain the underlying data is published at.

Other places to compare

Coos County sits in Oregon. That page carries the whole state's zone spread, its metro areas, and every other county in it with a page here.

More of Oregon

Counties with the same zones — 9a–9b

Matched on the exact zone set, not a dominant zone, so the winter answer on these pages really is the same one as here.

Gear

If you want to act on this

Each link opens an Amazon search rather than a product we picked. We have not tested these and do not rank them — the search is the honest version, and you choose.

Row cover and frost clothThe season here closes at the first fall freeze dated above — a cover buys back some of those days at the end.

As an Amazon Associate we earn from qualifying purchases. That costs you nothing extra, and it buys no influence over anything on this site: the dates come from NOAA normals and the zones from the USDA, and no product affects either.

Sources

Where these numbers come from

Hardiness zones are the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. Freeze dates and growing-season lengths are NOAA 1991–2020 Climate Normals, taken per station and cited above by name and NOAA ID.

County boundaries come from the Census ZCTA-to-county relation, which is what places each ZIP code — and which treats parishes, boroughs and census areas as county equivalents. No station is chosen to represent this county: every range above is taken across all of them and the count is stated, because picking one would be a judgement dressed as a measurement.