Frost dates for Window Rock, 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 29
typical year
Safe to plant
June 10
frost is over in 9 of 10 years
First fall frost
September 28
typical year
Growing season
121 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 | – | May 1 – 15 | – |
| Spinach | – | Apr 17 – May 8 | Aug 3 – 17 |
| Lettuce | – | May 1 – 22 | Aug 3 – 17 |
| Radishes | – | May 1 – Jun 12 | Aug 17 – 31 |
| Onions | – | May 1 – 15 | – |
| Potatoes | – | May 8 – 22 | – |
| Carrots | – | May 8 – 29 | Jul 6 – 20 |
| Beets | – | May 1 – 15 | Jul 20 – Aug 3 |
| Kale | Mar 20 – Apr 3 | May 1 – 15 | Jul 20 – Aug 3 |
| Broccoli | Mar 20 – Apr 3 | May 15 – 29 | Jul 20 – Aug 3 |
| Cabbage | Mar 6 – 20 | May 1 – 15 | Jul 20 – Aug 3 |
| Garlic | – | – | Aug 17 – Sep 7 |
| Warm-season crops | |||
| Tomatoes | Apr 15 – 29 | Jun 10 – 24 | – |
| Peppers | Apr 8 – 22 | Jun 17 – Jul 1 | – |
| Cucumbers | – | Jun 10 – Jul 1 | – |
| Zucchini | – | Jun 10 – Jul 8 | – |
| Pumpkins | – | Jun 10 – Jul 1 | – |
| Green beans | – | Jun 10 – Jul 20 | – |
| Sweet corn | – | Jun 10 – Jul 8 | – |
| Basil | May 6 – 20 | Jun 17 – 24 | – |
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 10 | May 29 | May 12 |
| Fall frost before | September 16 | September 28 | October 8 |
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 May 13 (June 1 in a late year), and the first one in fall around October 4.
Where these dates come from
NOAA weather station WINDOW ROCK AP, AZ US (USW00003029), 1991–2020 climate normals. It's the nearest station for 4 zip codes, all within 26 miles:
86504, 86515, 87320, 87328
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.