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Arizona

Planting zones in Navajo County, Arizona

This county spans USDA zones 6b to 7b, so there is no single zone for Navajo County and anyone who gives you one is rounding. 69% of its ZIP codes are zone 7a; the rest are not.

USDA zones 6b–7b 3 zones across 26 ZIP codes
ZIP codes 26 26 have a NOAA station within range
Weather stations 11 NOAA 1991–2020 normals, across 9,949 sq mi

Your ZIP code

Get the exact answer for your address

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

Works for all 40,502 US ZIP codes. Freeze dates need a NOAA station within 100 km; where there is none, the page says so rather than estimating one.

The growing season in Navajo County is closing

Nothing in the 32-crop table still has time to mature here. The first fall freeze normally arrives October 5 – October 24 across the 11 NOAA stations serving this county .

Your next season already has a date

The first job of it is πŸ§… Green Onions, start indoors, around February 25 – March 28 β€” counted back from a last spring freeze of April 22 – May 23 here.

Every spring date for your ZIP β†’

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

Growing season across Navajo County A one-year bar. Every one of the 11 NOAA stations serving this county counts May 23 to October 5 as growing season, 135 days. At least one counts April 22 to October 24, 185 days. The same figures are written out below this chart. JFMAMJJASONDMay 23October 5

All 11 stations agreeAt least one station

Every one of the 11 NOAA stations serving this county counts May 23 – October 5 as growing season (135 days). Widening to any single station gives April 22 – October 24 (185 days).

That is a 50-day difference inside one county β€” 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

Navajo County covers 3 hardiness zones. A guide that gives the county one zone has picked whichever is largest and rounded everyone else into it β€” fine for the 69% in zone 7a and wrong for the other 31%. Here is the actual split.

Zone ZIP codes Share  
7a 18 69%
6b 7 27%
7b 1 4%

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 April 22 – May 23
First fall freeze October 5 – October 24

Across the 11 NOAA stations serving this county. These are medians β€” half of years freeze later than the date shown β€” so treat the later end of each range as the cautious one.

The growing season runs 135–184 days depending which station you are nearest, as published by NOAA rather than computed from the dates above. Summer highs average 81.4–92.8 Β°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 2.2–7.9" across those 10 stations, against the rough inch a week β€” about 13 inches over the same 92 days β€” that a vegetable garden is usually reckoned to want. The middle station covers about 33% 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 88 Β°F summer afternoon drying the soil faster than a cool one.

Every ZIP code in Navajo 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 β€” 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
85901 7a Show Low AP, AZ 5.9 km
85902 7a Show Low AP, AZ 18.4 km
85911 7a Heber (Black Mesa) RS, AZ 35.7 km
85912 7a Show Low AP, AZ 19.0 km
85923 6b Heber (Black Mesa) RS, AZ 21.4 km
85926 7b Black Rvr Pumps, AZ 38.6 km
85928 7a Heber (Black Mesa) RS, AZ 14.0 km
85929 6b Pinetop 2E, AZ 6.6 km
85933 6b Heber (Black Mesa) RS, AZ 6.0 km
85934 6b Show Low AP, AZ 22.2 km
85935 6b Pinetop 2E, AZ 3.9 km
85937 7a Snowflake, AZ 9.4 km
85939 7a Snowflake, AZ 8.5 km
85942 7a Petrified Forest Np, AZ 13.9 km
86025 7a Holbrook, AZ 8.3 km
86029 7a Holbrook, AZ 14.6 km
86031 7a Painted Desert Np, AZ 42.5 km
86032 7a Holbrook, AZ 22.3 km
86033 7a Betatakin, AZ 25.4 km
86034 6b Keams Canyon, AZ 6.7 km
86039 7a Keams Canyon, AZ 38.3 km
86042 7a Keams Canyon, AZ 18.1 km
86043 7a Keams Canyon, AZ 30.7 km
86047 7a Winslow Muni AP, AZ 19.2 km
86054 7a Betatakin, AZ 6.9 km
86510 6b Keams Canyon, AZ 46.8 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 Navajo 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
πŸ§… Green Onions Start indoors February 25 – March 28 8 wk before
🌢️ Peppers Start indoors February 25 – March 28 8 wk before
πŸ₯¦ Broccoli Start indoors March 11 – April 11 6 wk before
πŸ₯¬ Cabbage Start indoors March 11 – April 11 6 wk before
πŸ₯¬ Collards Start indoors March 11 – April 11 6 wk before
πŸ₯¬ Kale Start indoors March 11 – April 11 6 wk before
πŸ₯¬ Leaf Lettuce Start indoors March 11 – April 11 6 wk before
πŸ«› Peas Direct sow March 11 – April 11 6 wk before
πŸ₯¬ Spinach Direct sow March 11 – April 11 6 wk before
🍠 Sweet Potato Start indoors March 11 – April 11 6 wk before
πŸ… Tomatoes Start indoors March 11 – April 11 6 wk before
πŸ₯¬ Bok Choy Start indoors March 18 – April 18 5 wk before
πŸ₯¬ Kohlrabi Start indoors March 18 – April 18 5 wk before
πŸ₯¬ Swiss Chard Start indoors March 18 – April 18 5 wk before
πŸ₯¬ Arugula Direct sow March 25 – April 25 4 wk before
πŸ₯¬ Baby Salad Greens Direct sow March 25 – April 25 4 wk before
πŸ₯• Beets Direct sow March 25 – April 25 4 wk before
πŸ§… Green Onions Direct sow March 25 – April 25 4 wk before
πŸ₯¬ Mustard Greens Direct sow March 25 – April 25 4 wk before
🌢️ Okra Start indoors March 25 – April 25 4 wk before
🌱 Radishes Direct sow March 25 – April 25 4 wk before
πŸ₯” Turnips Direct sow March 25 – April 25 4 wk before
πŸ₯¬ Cabbage Set out April 1 – May 2 3 wk before
πŸ₯• Carrots Direct sow April 1 – May 2 3 wk before
πŸ₯¬ Collards Direct sow April 1 – May 2 3 wk before
πŸ₯¬ Collards Set out April 1 – May 2 3 wk before
πŸ₯’ Cucumbers Start indoors April 1 – May 2 3 wk before
πŸ§… Green Onions Set out April 1 – May 2 3 wk before
πŸ₯¬ Kale Direct sow April 1 – May 2 3 wk before
πŸ₯¬ Kale Set out April 1 – May 2 3 wk before
πŸ₯¬ Kohlrabi Direct sow April 1 – May 2 3 wk before
πŸ₯¬ Kohlrabi Set out April 1 – May 2 3 wk before
πŸ₯¬ Leaf Lettuce Direct sow April 1 – May 2 3 wk before
πŸŽƒ Pumpkins Start indoors April 1 – May 2 3 wk before
πŸŽƒ Summer Squash Start indoors April 1 – May 2 3 wk before
πŸŽƒ Winter Squash Start indoors April 1 – May 2 3 wk before
πŸ₯’ Zucchini Start indoors April 1 – May 2 3 wk before
πŸ₯¬ Bok Choy Direct sow April 8 – May 9 2 wk before
πŸ₯¬ Bok Choy Set out April 8 – May 9 2 wk before
πŸ₯¦ Broccoli Set out April 8 – May 9 2 wk before
🌿 Cilantro Direct sow April 8 – May 9 2 wk before
πŸ₯¬ Leaf Lettuce Set out April 8 – May 9 2 wk before
πŸ₯¬ Swiss Chard Direct sow April 8 – May 9 2 wk before
πŸ₯¬ Swiss Chard Set out April 8 – May 9 2 wk before
🌿 Dill Direct sow April 15 – May 16 1 wk before
🫘 Bush Beans Direct sow April 29 – May 30 1 wk after
πŸ₯’ Cucumbers Set out April 29 – May 30 1 wk after
πŸŽƒ Pumpkins Direct sow April 29 – May 30 1 wk after
πŸŽƒ Pumpkins Set out April 29 – May 30 1 wk after
πŸŽƒ Summer Squash Direct sow April 29 – May 30 1 wk after
πŸŽƒ Summer Squash Set out April 29 – May 30 1 wk after
🌽 Sweet Corn Direct sow April 29 – May 30 1 wk after
πŸ… Tomatoes Set out April 29 – May 30 1 wk after
πŸŽƒ Winter Squash Direct sow April 29 – May 30 1 wk after
πŸŽƒ Winter Squash Set out April 29 – May 30 1 wk after
πŸ₯’ Zucchini Direct sow April 29 – May 30 1 wk after
πŸ₯’ Zucchini Set out April 29 – May 30 1 wk after
πŸ₯’ Cucumbers Direct sow May 6 – June 6 2 wk after
🌢️ Okra Direct sow May 6 – June 6 2 wk after
🌢️ Okra Set out May 6 – June 6 2 wk after
🌢️ Peppers Set out May 6 – June 6 2 wk after
🫘 Southern Peas Direct sow May 6 – June 6 2 wk after
🍠 Sweet Potato Set out May 6 – June 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 Navajo County

Zone 7a carries 58 of 74 perennial edibles; zone 6b carries 51. The best number is not always the warmest zone β€” 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 β€” a coastal zone 8 and an inland zone 8 are not the same summer.

How certain the freeze dates are in Navajo County Two rows. Each runs from the cautious date, which shortens the growing season, to the optimistic one. The median dates sit between them. Every figure is repeated in the text below this chart. JFMAMJJASONDLast spring freezeFirst fall freeze

Cautious β€” shortens the seasonMedian across stationsOptimistic

Last spring freeze
Plan to June 6 to be careful. Median April 22 – May 23 across 11 stations; April 8 is the optimistic end.
First fall freeze
Plan to September 24 to be careful. Median October 5 – October 24 across 11 stations; November 5 is the optimistic end.

NOAA publishes these as probabilities, not averages β€” 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 11 stations behind these numbers

The 11 NOAA stations serving Navajo County A relative sketch of where the stations sit, about 355 kilometres north to south. Each is named with its NOAA identifier in the station list on this page, which carries the same information as text. BETATAKIN, AZ US (USC00020750)BLACK RVR PUMPS, AZ US (USC00020808)HEBER (BLACK MESA) RS, AZ US (USC00023961)HOLBROOK, AZ US (USC00024089)KEAMS CANYON, AZ US (USC00024586)PAINTED DESERT NP, AZ US (USC00026190)PETRIFIED FOREST NP, AZ US (USC00026468)PINETOP 2E, AZ US (USC00026601)SHOW LOW AP, AZ US (USC00027855)SNOWFLAKE, AZ US (USC00028012)WINSLOW MUNI AP, AZ US (USW00023194) ~355 km north to south

All 11 NOAA stations whose normals this page quotes, spanning about 355 km north to south. Every one is named with its identifier in the station list below β€” 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 β€” 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
Betatakin, AZ USC00020750 May 7 October 15 159 days
Black Rvr Pumps, AZ USC00020808 May 16 October 13 149 days
Heber (Black Mesa) RS, AZ USC00023961 May 23 October 5 135 days
Holbrook, AZ USC00024089 April 22 October 24 184 days
Keams Canyon, AZ USC00024586 May 16 October 10 147 days
Painted Desert Np, AZ USC00026190 May 1 October 20 169 days
Petrified Forest Np, AZ USC00026468 May 4 October 16 162 days
Pinetop 2E, AZ USC00026601 May 22 October 6 138 days
Show Low AP, AZ USC00027855 May 5 October 15 162 days
Snowflake, AZ USC00028012 May 11 October 10 149 days
Winslow Muni AP, AZ USW00023194 April 27 October 18 174 days

These are medians, not averages β€” 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

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

More of Arizona

Counties with the same zones β€” 6b–7b

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 β€” the search is the honest version, and you choose.

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 β€” 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.