California
Planting zones in Siskiyou County, California
This county spans USDA zones 6b to 8b, so there is no single zone for Siskiyou County and anyone who gives you one is rounding. 62% of its ZIP codes are zone 8a; the rest are not.
Your ZIP code
Get the exact answer for your address
Everything above describes Siskiyou County, California 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.
Siskiyou County does not have one planting answer
Its own weather stations disagree about 18 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
- 107 days
KENO, OR US (USC00354403) - Longest season
- 262 days
ORLEANS, CA US (USC00046508)
155 days of growing season separate those two stations, and both serve ZIP codes in Siskiyou 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.
All 12 stations agreeAt least one station
Every one of the 12 NOAA stations serving this county counts June 6 – September 20 as growing season (106 days). Widening to any single station gives March 12 – November 26 (259 days).
That is a 153-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
Siskiyou County covers 4 hardiness zones. A guide that gives the county one zone has picked whichever is largest and rounded everyone else into it — fine for the 62% in zone 8a and wrong for the other 38%. Here is the actual split.
| Zone | ZIP codes | Share | |
|---|---|---|---|
| 8a | 13 | 62% | |
| 8b | 4 | 19% | |
| 6b | 2 | 10% | |
| 7b | 2 | 10% |
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
Across the 12 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 107–262 days depending which station you are nearest, as published by NOAA rather than computed from the dates above. Summer highs average 81.8–91.5 °F in June–August. That is past the point where tomato and pepper pollen fails and cool-season greens bolt, so in this county heat decides as much as frost does. Summer rain over the same months runs 1.1–1.7" across those 11 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 12% 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 87 °F summer afternoon drying the soil faster than a cool one.
Every ZIP code in Siskiyou 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 |
|---|---|---|---|
| 95568 | 8b | Orleans, CA | 19.9 km |
| 96014 | 8a | Callahan, CA | 6.7 km |
| 96023 | 6b | Keno, OR | 21.5 km |
| 96025 | 8a | Dunsmuir Trtmt Pl, CA | 3.7 km |
| 96027 | 8a | Orleans, CA | 26.7 km |
| 96031 | 8b | Cecilville, CA | 6.2 km |
| 96032 | 8a | Callahan, CA | 30.4 km |
| 96034 | 8a | Callahan, CA | 21.8 km |
| 96037 | 8a | Callahan, CA | 24.4 km |
| 96038 | 8a | Yreka, CA | 13.3 km |
| 96039 | 8b | Orleans, CA | 42.1 km |
| 96044 | 8a | Montague Siskiyou Co AP, CA | 23.9 km |
| 96050 | 8a | Yreka, CA | 30.6 km |
| 96057 | 7b | Mccloud, CA | 18.4 km |
| 96058 | 6b | Lava Beds Nat Mon, CA | 33.8 km |
| 96064 | 7b | Montague Siskiyou Co AP, CA | 9.3 km |
| 96067 | 8a | Mt Shasta, CA | 0.6 km |
| 96085 | 8a | Yreka, CA | 36.4 km |
| 96086 | 8b | Ruch, OR | 37.6 km |
| 96094 | 8a | Mt Shasta, CA | 20.3 km |
| 96097 | 8a | Yreka, CA | 6.1 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 Siskiyou County
Every date below is anchored on the last spring freeze at each station and reported as a range across all 12 of them, because no one station speaks for the county.
| Crop | Job | When | Offset |
|---|---|---|---|
| 🧅 Green Onions | Start indoors | January 15 – April 11 | 8 wk before |
| 🌶️ Peppers | Start indoors | January 15 – April 11 | 8 wk before |
| 🥦 Broccoli | Start indoors | January 29 – April 25 | 6 wk before |
| 🥬 Cabbage | Start indoors | January 29 – April 25 | 6 wk before |
| 🥬 Collards | Start indoors | January 29 – April 25 | 6 wk before |
| 🥬 Kale | Start indoors | January 29 – April 25 | 6 wk before |
| 🥬 Leaf Lettuce | Start indoors | January 29 – April 25 | 6 wk before |
| 🫛 Peas | Direct sow | January 29 – April 25 | 6 wk before |
| 🥬 Spinach | Direct sow | January 29 – April 25 | 6 wk before |
| 🍠 Sweet Potato | Start indoors | January 29 – April 25 | 6 wk before |
| 🍅 Tomatoes | Start indoors | January 29 – April 25 | 6 wk before |
| 🥬 Bok Choy | Start indoors | February 5 – May 2 | 5 wk before |
| 🥬 Kohlrabi | Start indoors | February 5 – May 2 | 5 wk before |
| 🥬 Swiss Chard | Start indoors | February 5 – May 2 | 5 wk before |
| 🥬 Arugula | Direct sow | February 12 – May 9 | 4 wk before |
| 🥬 Baby Salad Greens | Direct sow | February 12 – May 9 | 4 wk before |
| 🥕 Beets | Direct sow | February 12 – May 9 | 4 wk before |
| 🧅 Green Onions | Direct sow | February 12 – May 9 | 4 wk before |
| 🥬 Mustard Greens | Direct sow | February 12 – May 9 | 4 wk before |
| 🌶️ Okra | Start indoors | February 12 – May 9 | 4 wk before |
| 🌱 Radishes | Direct sow | February 12 – May 9 | 4 wk before |
| 🥔 Turnips | Direct sow | February 12 – May 9 | 4 wk before |
| 🥬 Cabbage | Set out | February 19 – May 16 | 3 wk before |
| 🥕 Carrots | Direct sow | February 19 – May 16 | 3 wk before |
| 🥬 Collards | Direct sow | February 19 – May 16 | 3 wk before |
| 🥬 Collards | Set out | February 19 – May 16 | 3 wk before |
| 🥒 Cucumbers | Start indoors | February 19 – May 16 | 3 wk before |
| 🧅 Green Onions | Set out | February 19 – May 16 | 3 wk before |
| 🥬 Kale | Direct sow | February 19 – May 16 | 3 wk before |
| 🥬 Kale | Set out | February 19 – May 16 | 3 wk before |
| 🥬 Kohlrabi | Direct sow | February 19 – May 16 | 3 wk before |
| 🥬 Kohlrabi | Set out | February 19 – May 16 | 3 wk before |
| 🥬 Leaf Lettuce | Direct sow | February 19 – May 16 | 3 wk before |
| 🎃 Pumpkins | Start indoors | February 19 – May 16 | 3 wk before |
| 🎃 Summer Squash | Start indoors | February 19 – May 16 | 3 wk before |
| 🎃 Winter Squash | Start indoors | February 19 – May 16 | 3 wk before |
| 🥒 Zucchini | Start indoors | February 19 – May 16 | 3 wk before |
| 🥬 Bok Choy | Direct sow | February 26 – May 23 | 2 wk before |
| 🥬 Bok Choy | Set out | February 26 – May 23 | 2 wk before |
| 🥦 Broccoli | Set out | February 26 – May 23 | 2 wk before |
| 🌿 Cilantro | Direct sow | February 26 – May 23 | 2 wk before |
| 🥬 Leaf Lettuce | Set out | February 26 – May 23 | 2 wk before |
| 🥬 Swiss Chard | Direct sow | February 26 – May 23 | 2 wk before |
| 🥬 Swiss Chard | Set out | February 26 – May 23 | 2 wk before |
| 🌿 Dill | Direct sow | March 5 – May 30 | 1 wk before |
| 🫘 Bush Beans | Direct sow | March 19 – June 13 | 1 wk after |
| 🥒 Cucumbers | Set out | March 19 – June 13 | 1 wk after |
| 🎃 Pumpkins | Direct sow | March 19 – June 13 | 1 wk after |
| 🎃 Pumpkins | Set out | March 19 – June 13 | 1 wk after |
| 🎃 Summer Squash | Direct sow | March 19 – June 13 | 1 wk after |
| 🎃 Summer Squash | Set out | March 19 – June 13 | 1 wk after |
| 🌽 Sweet Corn | Direct sow | March 19 – June 13 | 1 wk after |
| 🍅 Tomatoes | Set out | March 19 – June 13 | 1 wk after |
| 🎃 Winter Squash | Direct sow | March 19 – June 13 | 1 wk after |
| 🎃 Winter Squash | Set out | March 19 – June 13 | 1 wk after |
| 🥒 Zucchini | Direct sow | March 19 – June 13 | 1 wk after |
| 🥒 Zucchini | Set out | March 19 – June 13 | 1 wk after |
| 🥒 Cucumbers | Direct sow | March 26 – June 20 | 2 wk after |
| 🌶️ Okra | Direct sow | March 26 – June 20 | 2 wk after |
| 🌶️ Okra | Set out | March 26 – June 20 | 2 wk after |
| 🌶️ Peppers | Set out | March 26 – June 20 | 2 wk after |
| 🫘 Southern Peas | Direct sow | March 26 – June 20 | 2 wk after |
| 🍠 Sweet Potato | Set out | March 26 – June 20 | 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 Siskiyou County
Zone 8a carries 57 of 74 perennial edibles; zone 6b carries 51. 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 June 22 to be careful. Median March 12 – June 6 across 12 stations; January 26 is the optimistic end.
- First fall freeze
- Plan to September 6 to be careful. Median September 20 – November 26 across 12 stations; December 21 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 12 stations behind these numbers
All 12 NOAA stations whose normals this page quotes, spanning about 120 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 |
|---|---|---|---|---|
| Callahan, CA | USC00041316 | May 20 | October 5 | 135 days |
| Cecilville, CA | USC00041606 | April 27 | October 21 | 176 days |
| Dunsmuir Trtmt Pl, CA | USC00042574 | April 23 | October 27 | 185 days |
| Keno, OR | USC00354403 | June 5 | September 20 | 107 days |
| Lava Beds Nat Mon, CA | USC00044838 | June 6 | September 28 | 113 days |
| Mccloud, CA | USC00045449 | May 28 | September 30 | 123 days |
| Montague Siskiyou Co AP, CA | USW00024259 | May 12 | October 8 | 148 days |
| Mt Shasta, CA | USC00045983 | May 15 | October 6 | 143 days |
| Mt Shasta, CA | USW00024215 | May 6 | October 12 | 158 days |
| Orleans, CA | USC00046508 | March 12 | November 26 | 262 days |
| Ruch, OR | USC00357391 | May 4 | October 13 | 160 days |
| Yreka, CA | USC00049866 | April 30 | October 18 | 169 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
Siskiyou County sits in California. That page carries the whole state's zone spread, its metro areas, and every other county in it with a page here.
More of California
- Calaveras County, CA 8b–9b
- Lassen County, CA 6a–7a
- Plumas County, CA 6b–8a
- Lake County, CA 8b–9b
- Tehama County, CA 7a, 7b, 9a, 9b
- Tuolumne County, CA 6a, 6b, 7b, 8a, 8b, 9a, 9b
- Trinity County, CA 7b, 8b, 9a
- Modoc County, CA 6b–7a
- Inyo County, CA 7a, 8a, 8b, 9a
- Mariposa County, CA 7a, 8a, 8b, 9a, 9b
- Mono County, CA 6a–7a
- Nevada County, CA 6b, 8b, 9a, 9b
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.
- MulchFor the perennials nearest their cold limit in zone 6b, 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
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.