When to plant in Douglas, AZ
USDA Zone 8aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Douglas, Arizona — all computed from Douglas's nearest NOAA weather station.
Zone 8a means many perennials and even some tender shrubs overwinter in Douglas, while your frost dates still decide when annuals go out.
The average last spring frost in Douglas is now 10 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
DOUGLAS · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Douglas’s own odds, recorded at DOUGLAS.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 27 | Apr 7 | Mar 18 | Oct 20 | Nov 3 | Nov 19 |
| 32°F | Apr 12 | Mar 18 | Feb 27 | Oct 27 | Nov 13 | Nov 30 |
| 28°F | Mar 24 | Feb 27 | Jan 31 | Nov 5 | Nov 25 | Dec 9 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Douglas, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 26 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Douglas planting FAQ
When is the last spring frost in Douglas, AZ?
Douglas's average last spring frost falls near March 18 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Douglas, AZ?
Expect Douglas's first fall frost near November 13 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Douglas in?
Douglas is in USDA hardiness zone 8a. In zone 8a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Douglas?
There are roughly 240 frost-free days in Douglas (a long growing season), running from the average last frost around March 18 to the first fall frost near November 13.
When should I plant tomatoes in Douglas?
In Douglas, start tomato seeds indoors around January 21–February 4, then transplant seedlings outdoors around March 25 once the danger of frost has passed.
Never miss a window in Douglas
An email when it’s time to start seeds, transplant, and sow — timed to Douglas’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Sierra Vista Southeast · 65 km
- Sierra Vista · 76 km
- Vail · 129 km
- Nogales · 132 km
- Rio Rico · 138 km
- Green Valley · 147 km
- Sahuarita · 147 km
- Tanque Verde · 149 km
Frost dates recorded at DOUGLAS, 6 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Douglas, AZ — Frost Dates & Zone 8a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00022659. Retrieved from https://blissgarden.com/arizona/douglas.