When to plant in New River, AZ
USDA Zone 9bEverything below — frost dates, hardiness zone, and what to plant when in New River, Arizona — is derived from the closest NOAA station with complete climate normals.
A generous ~315-day season lets New River gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. These dates come from a station roughly 19 km away, the closest with full normals; terrain around New River (elevation, water, pavement) can move your real frost dates a few days either way. In zone 9b, frost is a minor factor for New River — most perennials thrive, and annual vegetables can go out early and stay late.
Frost probability
CAREFREE · 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 New River’s own odds, recorded at CAREFREE.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 2 | Mar 5 | Jan 31 | Nov 13 | Dec 1 | Dec 18 |
| 32°F | Mar 9 | Feb 4 | Jan 3 | Nov 24 | Dec 16 | Jan 15 |
| 28°F | Feb 22 | Jan 14 | Dec 19 | Dec 5 | Jan 1 | Feb 9 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Nothing new to sow or transplant outdoors in the next few weeks — a seasonal lull. Check the full-year calendar below for the next window.
Full-year planting calendar
Each bar is the exact window to take a planting action in New River, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 27 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.
New River planting FAQ
When is the last spring frost in New River, AZ?
Plan for the last spring frost in New River around February 4 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in New River, AZ?
Expect New River's first fall frost near December 16 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is New River in?
New River is in USDA hardiness zone 9b. In zone 9b, winters are mild — many tender perennials overwinter here.
How long is the growing season in New River?
New River has about 315 frost-free days — a long growing season — between the average last spring frost (February 4) and first fall frost (December 16).
When should I plant tomatoes in New River?
For New River, sow tomatoes indoors about December 10–December 24 and move the seedlings out around February 11, after the last spring frost.
Never miss a window in New River
An email when it’s time to start seeds, transplant, and sow — timed to New River’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Anthem · 5 km
- Peoria · 23 km
- Scottsdale · 30 km
- Sun City West · 34 km
- Phoenix · 35 km
- Sun City · 35 km
- Paradise Valley · 39 km
- El Mirage · 39 km
Frost dates recorded at CAREFREE, 19 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 New River, AZ — Frost Dates & Zone 9b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00021282. Retrieved from https://blissgarden.com/arizona/new-river.