What USDA hardiness zone is Douglas County, Oregon?

Douglas County, Oregon spans USDA hardiness zones 8b to 9a. 64% of its ZIP codes are zone 8b, so there is no single zone for the county.

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

The median last spring freeze runs March 19 – April 29 across the 11 NOAA weather stations serving Douglas County, Oregon, from NOAA 1991-2020 Climate Normals. Half of years freeze later than the median.

Oregon

Planting zones in Douglas County, Oregon

This county spans USDA zones 8b to 9a, so there is no single zone for Douglas County and anyone who gives you one is rounding. 64% of its ZIP codes are zone 8b; the rest are not.

USDA zones 8b–9a 2 zones across 25 ZIP codes

ZIP codes 25 25 have a NOAA station within range

Weather stations 11 NOAA 1991–2020 normals, across 5,036 sq mi

Your ZIP code

Get the exact answer for your address

Everything above describes Douglas 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.

Douglas County does not have one planting answer

Its own weather stations disagree about 16 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: 171 days
LOST CREEK DAM, OR US (USC00355055)
Longest season: 249 days
WINCHESTER BAY COAST GRD, OR US (USC00353193)

78 days of growing season separate those two stations, and both serve ZIP codes in Douglas 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 11 stations agreeAt least one station

Every one of the 11 NOAA stations serving this county counts April 29 – October 17 as growing season (171 days). Widening to any single station gives March 19 – November 24 (250 days).

That is a 79-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

Douglas 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 64% in zone 8b and wrong for the other 36%. Here is the actual split.

Zone	ZIP codes	Share
8b	16	64%
9a	9	36%

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 March 19 – April 29

First fall freeze October 17 – November 24

Across the 11 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 171–249 days depending which station you are nearest, as published by NOAA rather than computed from the dates above. Summer highs average 68.5–86.9 °F in June–August. Summer rain over the same months runs 1.4–3.4" across those 10 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 14% 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 83 °F summer afternoon drying the soil faster than a cool one.

Every ZIP code in Douglas 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
97410	8b	Riddle, OR	25.5 km
97416	9a	Riddle, OR	29.1 km
97417	8b	Riddle, OR	11.6 km
97429	8b	Riddle, OR	24.7 km
97435	8b	Drain, OR	3.5 km
97436	9a	Elkton 1Sw, OR	0.3 km
97441	9a	Winchester Bay Coast Grd, OR	7.9 km
97442	8b	Riddle, OR	19.7 km
97443	8b	Idleyld Park 4 NE, OR	13.7 km
97447	8b	Toketee Falls, OR	4.0 km
97457	8b	Riddle, OR	16.4 km
97462	8b	Elkton 3 SW, OR	19.2 km
97467	9a	Winchester Bay Coast Grd, OR	22.6 km
97469	8b	Riddle, OR	5.8 km
97470	8b	Roseburg Rgnl AP, OR	9.2 km
97471	9a	Roseburg Kqen, OR	9.9 km
97473	9a	Winchester Bay Coast Grd, OR	21.2 km
97479	8b	Winchester, OR	18.5 km
97481	9a	Roseburg Kqen, OR	19.5 km
97484	8b	Lost Creek Dam, OR	32.2 km
97486	9a	Winchester, OR	16.1 km
97494	8b	Winchester, OR	5.7 km
97495	8b	Winchester, OR	3.2 km
97496	9a	Riddle, OR	15.9 km
97499	8b	Drain, OR	10.3 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 Douglas County

Every date below is anchored on the last spring freeze at each station and reported as a range across all 11 of them, because no one station speaks for the county.

Crop	Job	When	Offset
🧅 Green Onions	Start indoors	January 22 – March 4	8 wk before
🌶️ Peppers	Start indoors	January 22 – March 4	8 wk before
🥦 Broccoli	Start indoors	February 5 – March 18	6 wk before
🥬 Cabbage	Start indoors	February 5 – March 18	6 wk before
🥬 Collards	Start indoors	February 5 – March 18	6 wk before
🥬 Kale	Start indoors	February 5 – March 18	6 wk before
🥬 Leaf Lettuce	Start indoors	February 5 – March 18	6 wk before
🫛 Peas	Direct sow	February 5 – March 18	6 wk before
🥬 Spinach	Direct sow	February 5 – March 18	6 wk before
🍠 Sweet Potato	Start indoors	February 5 – March 18	6 wk before
🍅 Tomatoes	Start indoors	February 5 – March 18	6 wk before
🥬 Bok Choy	Start indoors	February 12 – March 25	5 wk before
🥬 Kohlrabi	Start indoors	February 12 – March 25	5 wk before
🥬 Swiss Chard	Start indoors	February 12 – March 25	5 wk before
🥬 Arugula	Direct sow	February 19 – April 1	4 wk before
🥬 Baby Salad Greens	Direct sow	February 19 – April 1	4 wk before
🥕 Beets	Direct sow	February 19 – April 1	4 wk before
🧅 Green Onions	Direct sow	February 19 – April 1	4 wk before
🥬 Mustard Greens	Direct sow	February 19 – April 1	4 wk before
🌶️ Okra	Start indoors	February 19 – April 1	4 wk before
🌱 Radishes	Direct sow	February 19 – April 1	4 wk before
🥔 Turnips	Direct sow	February 19 – April 1	4 wk before
🥬 Cabbage	Set out	February 26 – April 8	3 wk before
🥕 Carrots	Direct sow	February 26 – April 8	3 wk before
🥬 Collards	Direct sow	February 26 – April 8	3 wk before
🥬 Collards	Set out	February 26 – April 8	3 wk before
🥒 Cucumbers	Start indoors	February 26 – April 8	3 wk before
🧅 Green Onions	Set out	February 26 – April 8	3 wk before
🥬 Kale	Direct sow	February 26 – April 8	3 wk before
🥬 Kale	Set out	February 26 – April 8	3 wk before
🥬 Kohlrabi	Direct sow	February 26 – April 8	3 wk before
🥬 Kohlrabi	Set out	February 26 – April 8	3 wk before
🥬 Leaf Lettuce	Direct sow	February 26 – April 8	3 wk before
🎃 Pumpkins	Start indoors	February 26 – April 8	3 wk before
🎃 Summer Squash	Start indoors	February 26 – April 8	3 wk before
🎃 Winter Squash	Start indoors	February 26 – April 8	3 wk before
🥒 Zucchini	Start indoors	February 26 – April 8	3 wk before
🥬 Bok Choy	Direct sow	March 5 – April 15	2 wk before
🥬 Bok Choy	Set out	March 5 – April 15	2 wk before
🥦 Broccoli	Set out	March 5 – April 15	2 wk before
🌿 Cilantro	Direct sow	March 5 – April 15	2 wk before
🥬 Leaf Lettuce	Set out	March 5 – April 15	2 wk before
🥬 Swiss Chard	Direct sow	March 5 – April 15	2 wk before
🥬 Swiss Chard	Set out	March 5 – April 15	2 wk before
🌿 Dill	Direct sow	March 12 – April 22	1 wk before
🫘 Bush Beans	Direct sow	March 26 – May 6	1 wk after
🥒 Cucumbers	Set out	March 26 – May 6	1 wk after
🎃 Pumpkins	Direct sow	March 26 – May 6	1 wk after
🎃 Pumpkins	Set out	March 26 – May 6	1 wk after
🎃 Summer Squash	Direct sow	March 26 – May 6	1 wk after
🎃 Summer Squash	Set out	March 26 – May 6	1 wk after
🌽 Sweet Corn	Direct sow	March 26 – May 6	1 wk after
🍅 Tomatoes	Set out	March 26 – May 6	1 wk after
🎃 Winter Squash	Direct sow	March 26 – May 6	1 wk after
🎃 Winter Squash	Set out	March 26 – May 6	1 wk after
🥒 Zucchini	Direct sow	March 26 – May 6	1 wk after
🥒 Zucchini	Set out	March 26 – May 6	1 wk after
🥒 Cucumbers	Direct sow	April 2 – May 13	2 wk after
🌶️ Okra	Direct sow	April 2 – May 13	2 wk after
🌶️ Okra	Set out	April 2 – May 13	2 wk after
🌶️ Peppers	Set out	April 2 – May 13	2 wk after
🫘 Southern Peas	Direct sow	April 2 – May 13	2 wk after
🍠 Sweet Potato	Set out	April 2 – May 13	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 Douglas County

Zone 8b carries 54 of 74 perennial edibles; zone 9a carries 46. 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 11 stations behind these numbers

All 11 NOAA stations whose normals this page quotes, spanning about 112 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
Drain, OR	USC00352406	April 16	October 25	193 days
Elkton 1Sw, OR	USC00352632	April 11	November 6	209 days
Elkton 3 SW, OR	USC00352633	March 21	November 12	240 days
Idleyld Park 4 NE, OR	USC00354126	April 27	October 19	176 days
Lost Creek Dam, OR	USC00355055	April 29	October 17	171 days
Riddle, OR	USC00357169	March 31	November 6	221 days
Roseburg Kqen, OR	USC00357331	March 23	November 18	237 days
Roseburg Rgnl AP, OR	USW00024231	March 19	November 20	245 days
Toketee Falls, OR	USC00358536	April 29	October 18	171 days
Winchester Bay Coast Grd, OR	USC00353193	March 25	November 24	249 days
Winchester, OR	USC00359461	March 31	November 5	215 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

Douglas 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 — 8b–9a

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.