What USDA hardiness zone is Worcester, MA?

Worcester, MA spans USDA hardiness zones 5b to 6b. 49% of its ZIP codes are zone 6a, so there is no single zone for the metro.

When is the last spring frost in Worcester, MA?

The median last spring freeze runs April 22 – May 12 across the 17 NOAA weather stations serving Worcester, MA, from NOAA 1991-2020 Climate Normals. Half of years freeze later than the median.

Place guide

Planting zones in Worcester, MA

This metro spans USDA zones 5b to 6b, so there is no single zone for Worcester, MA and anyone who gives you one is rounding. 49% of its ZIP codes are zone 6a; the rest are not.

USDA zones 5b–6b 3 zones across 85 ZIP codes

ZIP codes 85 85 have a NOAA station within range

Weather stations 17 NOAA 1991–2020 normals, across 1,511 sq mi

Your ZIP code

Get the exact answer for your address

Everything above describes Worcester, MA 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.

The growing season in Worcester, MA is closing

Nothing in the 32-crop table still has time to mature here. The first fall freeze normally arrives October 1 – October 21 across the 17 NOAA stations serving this metro area .

Your next season already has a date

The first job of it is 🧅 Green Onions, start indoors, around February 25 – March 17 — counted back from a last spring freeze of April 22 – May 12 here.

Every spring date for your ZIP →

These are ranges across the whole metro area. The ZIP lookup above gives the dates from your own nearest station instead.

All 17 stations agreeAt least one station

Every one of the 17 NOAA stations serving this metro area counts May 12 – October 1 as growing season (142 days). Widening to any single station gives April 22 – October 21 (182 days).

That is a 40-day difference inside one metro area — 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

Worcester, MA covers 3 hardiness zones. A guide that gives the metro one zone has picked whichever is largest and rounded everyone else into it — which is fine for the 49% in zone 6a and wrong for the other 51%. Here is the actual split.

Zone	ZIP codes	Share
6a	42	49%
6b	35	41%
5b	8	9%

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

Your freeze dates

Last spring freeze April 22 – May 12

First fall freeze October 1 – October 21

Those are the earliest and latest medians among the 17 stations serving this metro — not an average, and not one station standing in for the rest. Half of years freeze later than a station's own median.

The spread is the point. Even in a metro that is one hardiness zone throughout, its stations disagree about the last spring freeze. Hardiness zone and frost date measure different things — a zone is the average annual coldest night, a freeze date is when the season turns — and a place can be uniform in one and varied in the other. Use the tools below with your own ZIP rather than the ends of this range.

Your growing season

NOAA publishes a growing-season length for each station, and across the 17 stations serving Worcester, MA it runs 141–181 days . That figure is published, not computed from the two freeze dates — subtracting one from the other gives the wrong answer wherever a season crosses New Year. Mean summer high (June–August) runs 77–84 °F , below the 90 °F point where cool-season crops reliably bolt. Summer rain over the same months runs 11.0–13.3" across those 17 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 94% 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 80 °F summer afternoon drying the soil faster than a cool one.

When to start seeds in Worcester, MA

Every spring job for 63 crop dates, counted from this metro's own last spring freeze. Each is a range across all 17 stations — the earliest and latest that job falls anywhere in the metro — because no one station speaks for the whole area.

Crop	Job	When	Offset
Green Onions	Start indoors	February 25 – March 17	8 weeks before
Peppers	Start indoors	February 25 – March 17	8 weeks before
Broccoli	Start indoors	March 11 – March 31	6 weeks before
Cabbage	Start indoors	March 11 – March 31	6 weeks before
Collards	Start indoors	March 11 – March 31	6 weeks before
Kale	Start indoors	March 11 – March 31	6 weeks before
Leaf Lettuce	Start indoors	March 11 – March 31	6 weeks before
Peas	Direct sow	March 11 – March 31	6 weeks before
Spinach	Direct sow	March 11 – March 31	6 weeks before
Sweet Potato	Start indoors	March 11 – March 31	6 weeks before
Tomatoes	Start indoors	March 11 – March 31	6 weeks before
Bok Choy	Start indoors	March 18 – April 7	5 weeks before
Kohlrabi	Start indoors	March 18 – April 7	5 weeks before
Swiss Chard	Start indoors	March 18 – April 7	5 weeks before
Arugula	Direct sow	March 25 – April 14	4 weeks before
Baby Salad Greens	Direct sow	March 25 – April 14	4 weeks before
Beets	Direct sow	March 25 – April 14	4 weeks before
Green Onions	Direct sow	March 25 – April 14	4 weeks before
Mustard Greens	Direct sow	March 25 – April 14	4 weeks before
Okra	Start indoors	March 25 – April 14	4 weeks before
Radishes	Direct sow	March 25 – April 14	4 weeks before
Turnips	Direct sow	March 25 – April 14	4 weeks before
Cabbage	Set out	April 1 – April 21	3 weeks before
Carrots	Direct sow	April 1 – April 21	3 weeks before
Collards	Direct sow	April 1 – April 21	3 weeks before
Collards	Set out	April 1 – April 21	3 weeks before
Cucumbers	Start indoors	April 1 – April 21	3 weeks before
Green Onions	Set out	April 1 – April 21	3 weeks before
Kale	Direct sow	April 1 – April 21	3 weeks before
Kale	Set out	April 1 – April 21	3 weeks before
Kohlrabi	Direct sow	April 1 – April 21	3 weeks before
Kohlrabi	Set out	April 1 – April 21	3 weeks before
Leaf Lettuce	Direct sow	April 1 – April 21	3 weeks before
Pumpkins	Start indoors	April 1 – April 21	3 weeks before
Summer Squash	Start indoors	April 1 – April 21	3 weeks before
Winter Squash	Start indoors	April 1 – April 21	3 weeks before
Zucchini	Start indoors	April 1 – April 21	3 weeks before
Bok Choy	Direct sow	April 8 – April 28	2 weeks before
Bok Choy	Set out	April 8 – April 28	2 weeks before
Broccoli	Set out	April 8 – April 28	2 weeks before
Cilantro	Direct sow	April 8 – April 28	2 weeks before
Leaf Lettuce	Set out	April 8 – April 28	2 weeks before
Swiss Chard	Direct sow	April 8 – April 28	2 weeks before
Swiss Chard	Set out	April 8 – April 28	2 weeks before
Dill	Direct sow	April 15 – May 5	1 week before
Bush Beans	Direct sow	April 29 – May 19	1 week after
Cucumbers	Set out	April 29 – May 19	1 week after
Pumpkins	Direct sow	April 29 – May 19	1 week after
Pumpkins	Set out	April 29 – May 19	1 week after
Summer Squash	Direct sow	April 29 – May 19	1 week after
Summer Squash	Set out	April 29 – May 19	1 week after
Sweet Corn	Direct sow	April 29 – May 19	1 week after
Tomatoes	Set out	April 29 – May 19	1 week after
Winter Squash	Direct sow	April 29 – May 19	1 week after
Winter Squash	Set out	April 29 – May 19	1 week after
Zucchini	Direct sow	April 29 – May 19	1 week after
Zucchini	Set out	April 29 – May 19	1 week after
Cucumbers	Direct sow	May 6 – May 26	2 weeks after
Okra	Direct sow	May 6 – May 26	2 weeks after
Okra	Set out	May 6 – May 26	2 weeks after
Peppers	Set out	May 6 – May 26	2 weeks after
Southern Peas	Direct sow	May 6 – May 26	2 weeks after
Sweet Potato	Set out	May 6 – May 26	2 weeks after

The week offsets are conventional extension guidance and vary by variety; the freeze dates they are counted from are measured. For a single date rather than a range, run when do I start my seeds? with your own ZIP code.

What survives the winter changes across Worcester, MA

Of 74 perennial fruits, nuts, berries, vegetables and herbs, 51 come through the winter in zone 6a and only 48 in zone 5b. That is a different garden at each end of the same metro.

Zone	ZIPs	Survive
5b	8	48 of 74
6a	42	51 of 74
6b	35	51 of 74

The last column is the counterintuitive one, and it is why the totals do not simply rise as the winters get milder. Most temperate fruit needs a documented number of hours below about 45 °F to break dormancy and set a crop, so an apple fails in a winter that is too warm; currants and rhubarb cook in the summer heat that comes with it. See the full list with reasons.

Cautious — shortens the seasonMedian across stationsOptimistic

Last spring freeze: Plan to May 28 to be careful. Median April 22 – May 12 across 17 stations; April 9 is the optimistic end.
First fall freeze: Plan to September 18 to be careful. Median October 1 – October 21 across 17 stations; November 3 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 17 stations behind these numbers

All 17 NOAA stations whose normals this page quotes, spanning about 75 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 metro area.

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.

Every figure above comes from these, and each is named so you can check it. Which station serves a given ZIP code, and how far away it is, varies across the metro — the table below gives it per ZIP code rather than this page averaging it.

Station	NOAA ID	Last spring freeze	First fall freeze	Season
Ashburnham N, MA	USC00190192	May 5	October 7	152 days
Ashburnham, MA	USC00190190	May 2	October 13	163 days
Barre Falls Dam, MA	USC00190408	May 12	October 1	141 days
Belchertown, MA	USC00190562	May 3	October 14	164 days
Birch Hill Dam, MA	USC00190666	May 6	October 1	148 days
Buffumville Lake, MA	USC00190998	May 1	October 10	162 days
E Brimfield Lake, MA	USC00192107	April 28	October 15	169 days
Fitchburg Coop, MA	USC00192807	May 1	October 9	162 days
Fitchburg Muni AP, MA	USW00004780	April 29	October 11	164 days
Maynard 2, MA	USC00194580	May 2	October 6	156 days
Natick, MA	USC00195175	April 26	October 12	169 days
Orange Muni AP, MA	USW00054756	May 4	October 8	157 days
Southbridge 3 SW, MA	USC00197627	April 25	October 13	168 days
Tully Lake, MA	USC00198573	April 25	October 17	175 days
West Medway, MA	USC00199316	April 30	October 9	162 days
Woonsocket, RI	USC00379423	April 22	October 19	179 days
Worcester Rgnl AP, MA	USW00094746	April 23	October 21	181 days

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

Every ZIP code in Worcester, MA

Zones are published per ZIP code, not per metro area, so this is the exact answer rather than the metro area'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
01005	6a	Barre Falls Dam, MA	7.0 km
01031	6a	Belchertown, MA	13.9 km
01037	6a	Barre Falls Dam, MA	15.1 km
01068	6a	Barre Falls Dam, MA	8.7 km
01074	6a	Barre Falls Dam, MA	8.2 km
01083	6a	E Brimfield Lake, MA	12.3 km
01092	6a	E Brimfield Lake, MA	12.7 km
01094	6a	Barre Falls Dam, MA	11.2 km
01331	5b	Tully Lake, MA	8.4 km
01366	6a	Orange Muni AP, MA	12.6 km
01368	5b	Tully Lake, MA	5.3 km
01420	6a	Fitchburg Coop, MA	3.7 km
01430	6a	Ashburnham N, MA	1.8 km
01434	6a	Fitchburg Muni AP, MA	11.8 km
01436	5b	Birch Hill Dam, MA	4.5 km
01438	5b	Birch Hill Dam, MA	10.7 km
01440	5b	Ashburnham, MA	6.6 km
01451	6a	Maynard 2, MA	13.1 km
01452	5b	Barre Falls Dam, MA	7.7 km
01453	6a	Fitchburg Muni AP, MA	3.6 km
01462	6a	Fitchburg Muni AP, MA	4.5 km
01468	5b	Birch Hill Dam, MA	10.9 km
01473	6a	Ashburnham, MA	7.1 km
01475	5b	Birch Hill Dam, MA	6.8 km
01501	6a	Worcester Rgnl AP, MA	8.3 km
01503	6b	Maynard 2, MA	16.5 km
01504	6b	Woonsocket, RI	7.1 km
01505	6a	Worcester Rgnl AP, MA	16.0 km
01506	6a	E Brimfield Lake, MA	8.0 km
01507	6b	Buffumville Lake, MA	5.4 km
01510	6a	Fitchburg Muni AP, MA	16.5 km
01515	6a	E Brimfield Lake, MA	13.2 km
01516	6b	Buffumville Lake, MA	14.6 km
01518	6a	E Brimfield Lake, MA	1.1 km
01519	6b	Worcester Rgnl AP, MA	17.6 km
01520	6b	Worcester Rgnl AP, MA	7.2 km
01522	6a	Worcester Rgnl AP, MA	11.7 km
01523	6b	Fitchburg Muni AP, MA	10.0 km
01524	6b	Worcester Rgnl AP, MA	4.6 km
01525	6b	West Medway, MA	17.7 km
01527	6a	Worcester Rgnl AP, MA	11.7 km
01529	6b	Woonsocket, RI	9.3 km
01531	6a	Barre Falls Dam, MA	14.3 km
01532	6b	Worcester Rgnl AP, MA	19.6 km
01534	6b	West Medway, MA	17.5 km
01535	6a	Worcester Rgnl AP, MA	15.9 km
01536	6b	Worcester Rgnl AP, MA	15.5 km
01537	6a	Buffumville Lake, MA	4.8 km
01540	6b	Buffumville Lake, MA	3.9 km
01541	6a	Barre Falls Dam, MA	12.6 km
01542	6b	Worcester Rgnl AP, MA	7.9 km
01543	6a	Barre Falls Dam, MA	6.5 km
01545	6a	Worcester Rgnl AP, MA	13.2 km
01550	6b	Southbridge 3 SW, MA	3.2 km
01560	6b	Worcester Rgnl AP, MA	19.5 km
01561	6b	Fitchburg Muni AP, MA	13.0 km
01562	6a	Worcester Rgnl AP, MA	10.1 km
01564	6a	Fitchburg Muni AP, MA	11.7 km
01566	6a	E Brimfield Lake, MA	4.0 km
01568	6b	West Medway, MA	15.1 km
01569	6b	Woonsocket, RI	14.1 km
01570	6b	Buffumville Lake, MA	9.0 km
01571	6b	Buffumville Lake, MA	7.3 km
01581	6b	West Medway, MA	21.1 km
01583	6a	Worcester Rgnl AP, MA	13.5 km
01585	6a	E Brimfield Lake, MA	14.4 km
01588	6b	West Medway, MA	19.2 km
01590	6b	Buffumville Lake, MA	13.1 km
01602	6b	Worcester Rgnl AP, MA	1.8 km
01603	6a	Worcester Rgnl AP, MA	3.8 km
01604	6a	Worcester Rgnl AP, MA	8.9 km
01605	6a	Worcester Rgnl AP, MA	7.3 km
01606	6b	Worcester Rgnl AP, MA	8.1 km
01607	6a	Worcester Rgnl AP, MA	8.5 km
01608	6a	Worcester Rgnl AP, MA	6.0 km
01609	6b	Worcester Rgnl AP, MA	3.9 km
01610	6a	Worcester Rgnl AP, MA	5.9 km
01611	6b	Worcester Rgnl AP, MA	3.3 km
01612	6a	Worcester Rgnl AP, MA	5.4 km
01740	6b	Maynard 2, MA	13.1 km
01745	6b	Natick, MA	12.8 km
01747	6b	West Medway, MA	8.2 km
01756	6b	West Medway, MA	10.2 km
01757	6b	West Medway, MA	7.8 km
01772	6b	Natick, MA	15.5 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.

Your own ZIP

Work out your own dates

Each of these takes a ZIP code and answers for that ZIP alone, citing the station it used and how far away it is. There is a ZIP box in the header of every page.

What survives my winter?
Runs on the hardiness zone, so it answers for all of Worcester, MA at once — zone across 74 perennial fruits, berries, vegetables and herbs.
When do I start my seeds?
Dates every spring job from your own last freeze — sow indoors, set out, direct sow.
When do I sow the next round?
How often each crop is worth re-sowing, and when the next sowing is due.
What can I still plant?
Counts the growing days left before your first fall freeze, crop by crop.

Other places to compare

These metros span exactly the same zones — 5b–6b — so the same plants are in and out of range across them. The freeze dates and the spring calendar are their own.

Gardening in Massachusetts — zones 5b– 7b covers the whole state: how its 536 ZIP codes divide between 5 hardiness zones, and the freeze dates across every NOAA station in it.

Other metro areas in MA:

Barnstable Town, MA Zones 7a–7b
Springfield, MA Zones 6a–6b
Pittsfield, MA Zones 5b–6a
Amherst Town-Northampton, MA Zones 5b–6a
Boston-Cambridge-Newton, MA-NH Zones 5b–7a

All 388 metro areas, by state

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.

Trunk wrapZone 5b is cold enough that winter sun on a young trunk does more damage than the cold does.
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.
MulchFor the perennials nearest their cold limit in zone 5b, where an insulated crown is what decides whether they come back.

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

The hardiness zone is the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. The freeze dates are NOAA's 1991–2020 Climate Normals, read from every station whose normals cover a ZIP code in this metro. Nothing here is estimated, and no station stands in for another.

This page names no single station on purpose. Picking one to represent a metro sounds reasonable and is not: the station serving the most ZIP codes is an artifact of where ZIP centroids happen to fall, and it selects a lock on the Monongahela for Pittsburgh and a far southern suburb for Chicago. A range across every station is true; a single cited date for a whole metro is not.

All metro areas