Frost dates for Ft Thomas, 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
April 1
typical year
Safe to plant
April 18
frost is over in 9 of 10 years
First fall frost
November 6
typical year
Growing season
217 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 | – | Mar 4 – 18 | – |
| Spinach | – | Feb 18 – Mar 11 | Sep 11 – 25 |
| Lettuce | – | Mar 4 – 25 | Sep 11 – 25 |
| Radishes | – | Mar 4 – Apr 15 | Sep 25 – Oct 9 |
| Onions | – | Mar 4 – 18 | – |
| Potatoes | – | Mar 11 – 25 | – |
| Carrots | – | Mar 11 – Apr 1 | Aug 14 – 28 |
| Beets | – | Mar 4 – 18 | Aug 28 – Sep 11 |
| Kale | Jan 21 – Feb 4 | Mar 4 – 18 | Aug 28 – Sep 11 |
| Broccoli | Jan 21 – Feb 4 | Mar 18 – Apr 1 | Aug 28 – Sep 11 |
| Cabbage | Jan 7 – 21 | Mar 4 – 18 | Aug 28 – Sep 11 |
| Garlic | – | – | Sep 25 – Oct 16 |
| Warm-season crops | |||
| Tomatoes | Feb 21 – Mar 7 | Apr 18 – May 2 | – |
| Peppers | Feb 14 – 28 | Apr 25 – May 9 | – |
| Cucumbers | – | Apr 18 – May 9 | – |
| Zucchini | – | Apr 18 – May 16 | – |
| Pumpkins | – | Apr 18 – May 9 | – |
| Green beans | – | Apr 18 – Aug 28 | – |
| Sweet corn | – | Apr 18 – May 16 | – |
| Basil | Mar 14 – 28 | Apr 25 – May 2 | – |
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 | April 18 | April 1 | March 15 |
| Fall frost before | October 21 | November 6 | November 19 |
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 March 13 (April 3 in a late year), and the first one in fall around November 16.
Where these dates come from
NOAA weather station FT THOMAS 2 SW, AZ US (USC00023150), 1991–2020 climate normals. It's the nearest station for 3 zip codes, all within 10 miles:
85535, 85536, 85543
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.