Frost dates · USDA zone 9b
Frost dates for Glendale, AZ
Glendale, AZ sees its last 32 °F night of spring around January 20 and its first of fall around December 15 — a 331-day freeze-free season in a typical year.
Pick a sauce; the Plan Builder runs this station's dates and hands back the calendar, plant count and gear list.
Freeze odds, by date
| Odds | Last spring freeze after | First fall freeze before |
|---|---|---|
| 9 years in 10 | Dec 23 (prior winter) | Jan 7 (next year) |
| Median — 1 year in 2 | Jan 20 | Dec 15 |
| 1 year in 10 | Feb 18 | Nov 28 |
The top row is the risky edge: in 9 years of 10 a spring freeze still comes after it, so tender transplants set out then need cover. The bottom row is the cautious date — only 1 year in 10 freezes after it — and the one to plan uncovered tender transplants against. Freeze-free season: 331 days median, at least 297 in 9 years of 10, at least 358 days in 1 year of 10. NOAA ranks season length year by year, so it is not the gap between two rows above. A hard freeze (28 °F) has a median last date of Jan 3 and first of Dec 29.
Glendale planting calendar, 2027
Every row runs from the median last frost (Jan 20) and median first frost (Dec 15) above, using each cultivar's days to maturity. Same engine as the Plan Builder.
| Crop | Start indoors | Transplant / plant | First harvest | Days |
|---|---|---|---|---|
| Hardneck GarlicSiberian (porcelain hardneck) | — | Oct 15prior fall | Jun 12 | 240 from sow |
| Spanish OnionYellow Sweet Spanish (long-day) | Oct 28 | Dec 23 | Apr 12 | 110 from transplant |
| Mustard greensGarnet Giant (Brassica juncea) | Direct sow | Jan 20 | Feb 19 | 30 from sow |
| CilantroSlow Bolt (Coriandrum sativum) | Jan 6 | Jan 6 | Feb 20 | 45 from sow |
| Genovese BasilGenovese | Dec 23 | Feb 3 | Apr 4 | 60 from transplant |
| CayenneLong Slim Cayenne (Capsicum annuum) | Nov 25 | Jan 27 | Apr 12 | 75 from transplant |
| HabaneroOrange Habanero (Capsicum chinense) | Nov 11 | Feb 3 | May 9 | 95 from transplant |
| JalapeñoEarly Jalapeño (Capsicum annuum) | Nov 25 | Jan 27 | Apr 12 | 75 from transplant |
| Marconi Red PepperMarconi Red (Capsicum annuum) | Nov 25 | Jan 27 | Apr 17 | 80 from transplant |
| SerranoSerrano Tampiqueño (Capsicum annuum) | Nov 25 | Jan 27 | Apr 17 | 80 from transplant |
| Nantes CarrotScarlet Nantes | Jan 6 | Jan 6 | Mar 17 | 70 from sow |
| TomatilloToma Verde | Dec 9 | Jan 27 | Apr 7 | 70 from transplant |
| Roma TomatoRoma VF (determinate paste) | Dec 9 | Jan 27 | Apr 12 | 75 from transplant |
| San Marzano TomatoSan Marzano (indeterminate paste) | Dec 9 | Jan 27 | Apr 17 | 80 from transplant |
Tight means first harvest lands within two weeks of the median first fall frost: start that crop indoors on time or cover it in fall.
What sauce can Glendale grow?
Each sauce, scheduled for a Glendale container garden: when the first seeds go in and when enough fruit has ripened for one batch.
Glendale frost questions
When is the last frost in Glendale, AZ?
The median last 32 °F freeze at YOUNGTOWN, AZ is January 20: half of years see a later one. One year in ten, a freeze still comes after February 18; nine years in ten, it comes after December 23 (prior winter). Source: NOAA NCEI 1991–2020 U.S. Climate Normals.
When is the first frost in Glendale, AZ?
The median first 32 °F freeze of fall is December 15. One year in ten it arrives before November 28; nine years in ten, before January 7 (next year).
How long is the growing season in Glendale, AZ?
331 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 297 days; one year in ten, at least 358 days.
What growing zone is Glendale, AZ?
USDA hardiness zone 9b, per the 2023 USDA Plant Hardiness Zone Map for ZIP 85301. A zone describes the coldest winter night, not when frost ends, so it is the wrong number for a planting calendar — the frost dates on this page are the right one.
When should I plant tomatoes in Glendale, AZ?
Start Roma VF (determinate paste) seeds indoors around Dec 9 and transplant around Jan 27, 1 week after the median last frost. To cut the freeze risk to one year in ten, wait for Feb 18. First ripe fruit lands around Apr 12.
When should I plant peppers in Glendale, AZ?
Sow jalapeño indoors on a heat mat around Nov 25; transplant no earlier than Jan 27, and wait past it until nights hold above 50 °F — that can run weeks later. First green pods around Apr 12.
Nearby in Arizona
- Phoenixlast frost Jan 8
- Avondalelast frost Jan 7
- Surpriselast frost Feb 5
- Tempelast frost Feb 13
- Peorialast frost Feb 5
- Scottsdalelast frost Jan 27
All Arizona frost dates → · How frost-date math drives a sowing calendar →