When to plant in Casas Adobes, AZ
USDA Zone 9aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Casas Adobes, Arizona — all computed from Casas Adobes's nearest NOAA weather station.
With about 281 frost-free days, Casas Adobes supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. In zone 9a, frost is a minor factor for Casas Adobes — most perennials thrive, and annual vegetables can go out early and stay late.
Frost probability
TOHONO CHUL · 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 Casas Adobes’s own odds, recorded at TOHONO CHUL.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 9 | Mar 17 | Feb 28 | Nov 2 | Nov 21 | Dec 6 |
| 32°F | Mar 18 | Feb 26 | Jan 29 | Nov 17 | Dec 4 | Dec 19 |
| 28°F | Feb 27 | Feb 1 | Dec 31 | Nov 30 | Dec 17 | Jan 16 |
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 Casas Adobes, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 9 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.
Casas Adobes planting FAQ
When is the last spring frost in Casas Adobes, AZ?
Casas Adobes's average last spring frost falls near February 26 — 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 Casas Adobes, AZ?
The first fall frost in Casas Adobes typically arrives around December 4 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Casas Adobes in?
Casas Adobes is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Casas Adobes?
Casas Adobes has about 281 frost-free days — a long growing season — between the average last spring frost (February 26) and first fall frost (December 4).
When should I plant tomatoes in Casas Adobes?
For Casas Adobes, sow tomatoes indoors about January 1–January 15 and move the seedlings out around March 5, after the last spring frost.
Never miss a window in Casas Adobes
An email when it’s time to start seeds, transplant, and sow — timed to Casas Adobes’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Flowing Wells · 5 km
- Tucson Mountains · 9 km
- Oro Valley · 9 km
- Catalina Foothills · 13 km
- Marana · 18 km
- Tucson Estates · 21 km
- Drexel Heights · 22 km
- Tucson · 25 km
Frost dates recorded at TOHONO CHUL, 3 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 Casas Adobes, AZ — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00028590. Retrieved from https://blissgarden.com/arizona/casas-adobes.