What USDA hardiness zone is Tillamook County, Oregon?

Tillamook County, Oregon spans USDA hardiness zones 8b to 9b. 69% of its ZIP codes are zone 9a, so there is no single zone for the county.

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

The median last spring freeze runs March 17 – April 22 across the 4 NOAA weather stations serving Tillamook County, Oregon, from NOAA 1991-2020 Climate Normals. Half of years freeze later than the median.

Oregon

Planting zones in Tillamook County, Oregon

This county spans USDA zones 8b to 9b, so there is no single zone for Tillamook County and anyone who gives you one is rounding. 69% of its ZIP codes are zone 9a; the rest are not.

USDA zones 8b–9b 3 zones across 13 ZIP codes

ZIP codes 13 13 have a NOAA station within range

Weather stations 4 NOAA 1991–2020 normals, across 1,102 sq mi

Your ZIP code

Get the exact answer for your address

Everything above describes Tillamook 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.

Tillamook County does not have one planting answer

Its own weather stations disagree about 13 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: 183 days
TILLAMOOK, OR US (USC00358494)
Longest season: 251 days
CLOVERDALE, OR US (USC00351682)

68 days of growing season separate those two stations, and both serve ZIP codes in Tillamook 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 4 stations agreeAt least one station

Every one of the 4 NOAA stations serving this county counts April 22 – October 21 as growing season (182 days). Widening to any single station gives March 17 – November 22 (250 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

Tillamook County covers 3 hardiness zones. A guide that gives the county one zone has picked whichever is largest and rounded everyone else into it — fine for the 69% in zone 9a and wrong for the other 31%. Here is the actual split.

Zone	ZIP codes	Share
9a	9	69%
8b	3	23%
9b	1	8%

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 17 – April 22

First fall freeze October 21 – November 22

Across the 4 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 183–251 days depending which station you are nearest, as published by NOAA rather than computed from the dates above. Summer highs average 66.9–69.9 °F in June–August. Summer rain over the same months runs 4.9–5.8" 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 42% of it, so expect to make up the rest. The inches are NOAA's published normals; the inch a week is a rule of thumb, and it takes no account of a 68 °F summer afternoon drying the soil faster than a cool one.

Every ZIP code in Tillamook 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
97107	9a	Tillamook, OR	12.2 km
97108	8b	Tillamook 6Se, OR	18.5 km
97112	9a	Cloverdale, OR	7.9 km
97118	9a	Tillamook, OR	12.5 km
97122	8b	Cloverdale, OR	7.1 km
97130	9a	Tillamook, OR	29.3 km
97131	8b	Tillamook, OR	28.7 km
97134	9a	Tillamook, OR	9.3 km
97135	9b	Cloverdale, OR	5.5 km
97136	9a	Tillamook, OR	20.4 km
97141	9a	Tillamook 6Se, OR	8.9 km
97147	9a	Tillamook, OR	25.9 km
97149	9a	Otis 2 NE, OR	8.9 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 Tillamook County

Every date below is anchored on the last spring freeze at each station and reported as a range across all 4 of them, because no one station speaks for the county.

Crop	Job	When	Offset
🧅 Green Onions	Start indoors	January 20 – February 25	8 wk before
🌶️ Peppers	Start indoors	January 20 – February 25	8 wk before
🥦 Broccoli	Start indoors	February 3 – March 11	6 wk before
🥬 Cabbage	Start indoors	February 3 – March 11	6 wk before
🥬 Collards	Start indoors	February 3 – March 11	6 wk before
🥬 Kale	Start indoors	February 3 – March 11	6 wk before
🥬 Leaf Lettuce	Start indoors	February 3 – March 11	6 wk before
🫛 Peas	Direct sow	February 3 – March 11	6 wk before
🥬 Spinach	Direct sow	February 3 – March 11	6 wk before
🍠 Sweet Potato	Start indoors	February 3 – March 11	6 wk before
🍅 Tomatoes	Start indoors	February 3 – March 11	6 wk before
🥬 Bok Choy	Start indoors	February 10 – March 18	5 wk before
🥬 Kohlrabi	Start indoors	February 10 – March 18	5 wk before
🥬 Swiss Chard	Start indoors	February 10 – March 18	5 wk before
🥬 Arugula	Direct sow	February 17 – March 25	4 wk before
🥬 Baby Salad Greens	Direct sow	February 17 – March 25	4 wk before
🥕 Beets	Direct sow	February 17 – March 25	4 wk before
🧅 Green Onions	Direct sow	February 17 – March 25	4 wk before
🥬 Mustard Greens	Direct sow	February 17 – March 25	4 wk before
🌶️ Okra	Start indoors	February 17 – March 25	4 wk before
🌱 Radishes	Direct sow	February 17 – March 25	4 wk before
🥔 Turnips	Direct sow	February 17 – March 25	4 wk before
🥬 Cabbage	Set out	February 24 – April 1	3 wk before
🥕 Carrots	Direct sow	February 24 – April 1	3 wk before
🥬 Collards	Direct sow	February 24 – April 1	3 wk before
🥬 Collards	Set out	February 24 – April 1	3 wk before
🥒 Cucumbers	Start indoors	February 24 – April 1	3 wk before
🧅 Green Onions	Set out	February 24 – April 1	3 wk before
🥬 Kale	Direct sow	February 24 – April 1	3 wk before
🥬 Kale	Set out	February 24 – April 1	3 wk before
🥬 Kohlrabi	Direct sow	February 24 – April 1	3 wk before
🥬 Kohlrabi	Set out	February 24 – April 1	3 wk before
🥬 Leaf Lettuce	Direct sow	February 24 – April 1	3 wk before
🎃 Pumpkins	Start indoors	February 24 – April 1	3 wk before
🎃 Summer Squash	Start indoors	February 24 – April 1	3 wk before
🎃 Winter Squash	Start indoors	February 24 – April 1	3 wk before
🥒 Zucchini	Start indoors	February 24 – April 1	3 wk before
🥬 Bok Choy	Direct sow	March 3 – April 8	2 wk before
🥬 Bok Choy	Set out	March 3 – April 8	2 wk before
🥦 Broccoli	Set out	March 3 – April 8	2 wk before
🌿 Cilantro	Direct sow	March 3 – April 8	2 wk before
🥬 Leaf Lettuce	Set out	March 3 – April 8	2 wk before
🥬 Swiss Chard	Direct sow	March 3 – April 8	2 wk before
🥬 Swiss Chard	Set out	March 3 – April 8	2 wk before
🌿 Dill	Direct sow	March 10 – April 15	1 wk before
🫘 Bush Beans	Direct sow	March 24 – April 29	1 wk after
🥒 Cucumbers	Set out	March 24 – April 29	1 wk after
🎃 Pumpkins	Direct sow	March 24 – April 29	1 wk after
🎃 Pumpkins	Set out	March 24 – April 29	1 wk after
🎃 Summer Squash	Direct sow	March 24 – April 29	1 wk after
🎃 Summer Squash	Set out	March 24 – April 29	1 wk after
🌽 Sweet Corn	Direct sow	March 24 – April 29	1 wk after
🍅 Tomatoes	Set out	March 24 – April 29	1 wk after
🎃 Winter Squash	Direct sow	March 24 – April 29	1 wk after
🎃 Winter Squash	Set out	March 24 – April 29	1 wk after
🥒 Zucchini	Direct sow	March 24 – April 29	1 wk after
🥒 Zucchini	Set out	March 24 – April 29	1 wk after
🥒 Cucumbers	Direct sow	March 31 – May 6	2 wk after
🌶️ Okra	Direct sow	March 31 – May 6	2 wk after
🌶️ Okra	Set out	March 31 – May 6	2 wk after
🌶️ Peppers	Set out	March 31 – May 6	2 wk after
🫘 Southern Peas	Direct sow	March 31 – May 6	2 wk after
🍠 Sweet Potato	Set out	March 31 – May 6	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 Tillamook County

Zone 8b carries 54 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.

Cautious — shortens the seasonMedian across stationsOptimistic

Last spring freeze: Plan to May 13 to be careful. Median March 17 – April 22 across 4 stations; February 9 is the optimistic end.
First fall freeze: Plan to September 27 to be careful. Median October 21 – November 22 across 4 stations; December 31 is the optimistic end.

NOAA publishes these as probabilities, not averages — the middle figure is a median, so half of years fall either side of it. The cautious end is the 10% tail: in roughly nine years in ten the freeze falls on the safe side of it.

The 4 stations behind these numbers

All 4 NOAA stations whose normals this page quotes, spanning about 47 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
Cloverdale, OR	USC00351682	March 17	November 22	251 days
Otis 2 NE, OR	USC00356366	April 4	November 16	227 days
Tillamook 6Se, OR	USC00358498	April 5	November 4	219 days
Tillamook, OR	USC00358494	April 22	October 21	183 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

Tillamook 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–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.