Frost dates for Diamond M Rch, AZ
When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.
Last spring frost
May 17
typical year
Safe to plant
June 4
frost is over in 9 of 10 years
First fall frost
October 10
typical year
Growing season
146 days
frost-free, typical year
Frost watch this week
Tonight's and the next six nights' lows from the National Weather Service forecast for the station's location. Frost: 32°F or colder. Possible frost: 33–36°F, mostly in low spots on clear, still nights.
When to plant
Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.
| Crop | Start indoors | Plant outside | Fall planting |
|---|---|---|---|
| Cool-season crops | |||
| Peas | – | Apr 19 – May 3 | – |
| Spinach | – | Apr 5 – 26 | Aug 15 – 29 |
| Lettuce | – | Apr 19 – May 10 | Aug 15 – 29 |
| Radishes | – | Apr 19 – May 31 | Aug 29 – Sep 12 |
| Onions | – | Apr 19 – May 3 | – |
| Potatoes | – | Apr 26 – May 10 | – |
| Carrots | – | Apr 26 – May 17 | Jul 18 – Aug 1 |
| Beets | – | Apr 19 – May 3 | Aug 1 – 15 |
| Kale | Mar 8 – 22 | Apr 19 – May 3 | Aug 1 – 15 |
| Broccoli | Mar 8 – 22 | May 3 – 17 | Aug 1 – 15 |
| Cabbage | Feb 22 – Mar 8 | Apr 19 – May 3 | Aug 1 – 15 |
| Garlic | – | – | Aug 29 – Sep 19 |
| Warm-season crops | |||
| Tomatoes | Apr 9 – 23 | Jun 4 – 18 | – |
| Peppers | Apr 2 – 16 | Jun 11 – 25 | – |
| Cucumbers | – | Jun 4 – 25 | – |
| Zucchini | – | Jun 4 – Jul 2 | – |
| Pumpkins | – | Jun 4 – 25 | – |
| Green beans | – | Jun 4 – Aug 1 | – |
| Sweet corn | – | Jun 4 – Jul 2 | – |
| Basil | Apr 30 – May 14 | Jun 11 – 18 | – |
Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.
The year at a glance
Start indoors Plant outside Fall planting
The chance of frost, by date
| 1 year in 10 | Half of years | 9 years in 10 | |
|---|---|---|---|
| Spring frost after | June 4 | May 17 | May 1 |
| Fall frost before | September 28 | October 10 | October 26 |
Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.
Hard freeze (28°F)
A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around April 30 (May 17 in a late year), and the first one in fall around October 23.
Where these dates come from
NOAA weather station DIAMOND M RCH, AZ US (USC00022527), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 28 miles:
86434, 86437
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.