What does USDA hardiness zone 5a mean in Nevada?

Zone 5a means an average annual extreme minimum winter temperature of −20 to −15 °F — the standard USDA measure of which perennials survive winter. 3 locations in Nevada fall in this zone. It does not set planting dates; see the frost calendar below for that.

Where in Nevada's zone 5a is the growing season longest?

Osino runs the longest season on this page at about 111 days; Ely is shortest at about 91 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.

When should I plant tomatoes in Nevada's zone 5a?

Using Wells's frost dates (this page's median-season location): start seeds indoors about Apr 9 – Apr 23, then transplant outside about Jun 11 – Jun 18. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.

Does every location in Nevada's zone 5a have the same frost dates?

No — they do not all share a weather station, so frost dates vary by a week or more across the 3 locations listed (see the table above for each location's own dates).

USDA zone 5a in Nevada

−20 to −15 °F avg. annual extreme minimum · 3 locations in this group · NOAA 1991–2020 normals

USDA plant hardiness zone 5a covers 3 locations across Nevada (average annual extreme minimum −20 to −15 °F): Ely, NV, Osino, NV, Wells, NV. Average last spring frost across this group ranges May 29 (Osino) to June 12 (Ely), and growing seasons run 91–111 days (Ely to Osino) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Nevada location's own frost dates; the printable planting calendar uses Wells, this group's median-season location.

USDA zone: 5a−20 to −15 °F
Last frost range: May 29–Jun 12avg, 32°F
First frost range: Sep 13–Sep 18avg, 32°F
Growing season range: 91–111days

Locations in this group

Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.

Own frost dates per location.
Location	Also covers	Nearest station	Last frost	First frost	Season (days)
Ely	Ruth	Ely Yelland Fld Ap	Jun 12	Sep 13	91
Osino	—	Elko Rgnl Ap	May 29	Sep 18	111
Wells *	—	Arthur 4nw	Jun 4	Sep 18	105

* Wells is this group's median-season location — the calendar below is computed from its data.

Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.

Planting calendar (Wells, representative)

Computed from Wells's average frost dates — the median-season location in this Nevadazone 5a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).

Crop

JanFebMarAprMayJunJulAugSepOctNovDec

Tomato

Pepper

Cucumber

Summer squash / zucchini

Start indoors
Plant out
Fall sowing
First harvest

Planting windows for Wells (Nevada, zone 5a), this group's representative location.
Crop	Frost tolerance	Start indoors	Plant out	First harvest	Fall planting	Season fit
Tomato	Tender	Apr 9 – Apr 23	Jun 11 – Jun 18	Aug 10 – Aug 30	—	matures comfortably
Pepper	Very tender	Mar 26 – Apr 9	Jun 18 – Jun 25	Aug 17 – Sep 16	—	matures, but with little margin
Cucumber	Tender	May 7 – May 14	Jun 11 – Jun 18	Jul 31 – Aug 20	—	matures comfortably
Summer squash / zucchini	Tender	—	Jun 11 – Jun 18	Jul 26 – Aug 10	—	matures comfortably
Bush bean	Tender	—	Jun 11 – Jun 18	Jul 31 – Aug 10	Jul 20 – Jul 30	matures comfortably
Sweet corn	Tender	—	Jun 4 – Jun 18	Aug 3 – Sep 2	—	matures comfortably
Basil	Very tender	Apr 23 – May 7	Jun 11 – Jun 18	Jul 11 – Jul 26	—	matures comfortably
Lettuce	Half-hardy	Apr 23 – May 7	May 7 – May 21	Jun 21 – Jul 6	Jul 6 – Jul 21	matures comfortably
Pea	Hardy	—	Apr 23 – May 7	Jun 17 – Jul 2	Jun 26 – Jul 11	matures comfortably
Spinach	Hardy	—	Apr 23 – May 7	Jun 2 – Jun 12	Jul 16 – Jul 26	matures comfortably
Carrot	Half-hardy	—	May 14 – May 21	Jul 13 – Aug 2	Jun 16 – Jul 6	matures comfortably
Broccoli	Half-hardy	Apr 9 – Apr 23	May 7 – May 21	Jul 1 – Jul 21	Jun 21 – Jul 11	matures comfortably

Which crops fit this growing season

Using Wells's own 105-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 11 of 12 crops mature here with comfortable margin, 1matures with little room to spare. The tightest fits: pepper (+2 day margin). A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.

Frost & freeze dates (Wells)

From NOAA's 1991–2020 Climate Normals at station USC00260438. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.

Freeze probabilities by temperature threshold (MM/DD, NOAA 1991–2020), Wells.
Threshold	Last spring — avg	Last spring — 90%-safe	First fall — avg	First fall — 90%-safe	Season (days)
36°F	—	—	—	—	80
32°F (freeze)	Jun 4	Jun 20	Sep 18	Oct 2	105
28°F	May 18	Jun 9	Sep 29	Oct 16	133
24°F	Apr 30	May 20	Oct 11	Oct 28	163

Growing degree days

Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 3 locations is 1,951; Wells's own reading is shown below.

Annual growing degree days for Wells (°F·days, NOAA 1991–2020).
Model	°F·days	Used for
Base 50°F (warm-season)	1,704	standard warm-season base (tomato, corn, beans)
Base 40°F (cool-season)	3,504	cool-season crops (brassicas, greens)

Hardiness zone 5a in Nevada

Zone 5a means an average annual extreme minimum winter temperature of about −20 to −15 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Nevada spans 10 hardiness zones in this dataset — see all Nevada locations for the full range, including zones5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b.

Explore zone 5a in other states at zone 5a, or see all USDA hardiness zones.

Frequently asked questions

What does USDA hardiness zone 5a mean in Nevada?: Zone 5a means an average annual extreme minimum winter temperature of −20 to −15 °F — the standard USDA measure of which perennials survive winter. 3 locations in Nevada fall in this zone. It does not set planting dates; see the frost calendar below for that.
Where in Nevada's zone 5a is the growing season longest?: Osino runs the longest season on this page at about 111 days; Ely is shortest at about 91 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
When should I plant tomatoes in Nevada's zone 5a?: Using Wells's frost dates (this page's median-season location): start seeds indoors about Apr 9 – Apr 23, then transplant outside about Jun 11 – Jun 18. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
Does every location in Nevada's zone 5a have the same frost dates?: No — they do not all share a weather station, so frost dates vary by a week or more across the 3 locations listed (see the table above for each location's own dates).

Sources & method

Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.