Frost dates for Roxborough Sp, CO
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 16
typical year
Safe to plant
June 1
frost is over in 9 of 10 years
First fall frost
October 1
typical year
Growing season
136 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 18 – May 2 | – |
| Spinach | – | Apr 4 – 25 | Aug 6 – 20 |
| Lettuce | – | Apr 18 – May 9 | Aug 6 – 20 |
| Radishes | – | Apr 18 – May 30 | Aug 20 – Sep 3 |
| Onions | – | Apr 18 – May 2 | – |
| Potatoes | – | Apr 25 – May 9 | – |
| Carrots | – | Apr 25 – May 16 | Jul 9 – 23 |
| Beets | – | Apr 18 – May 2 | Jul 23 – Aug 6 |
| Kale | Mar 7 – 21 | Apr 18 – May 2 | Jul 23 – Aug 6 |
| Broccoli | Mar 7 – 21 | May 2 – 16 | Jul 23 – Aug 6 |
| Cabbage | Feb 21 – Mar 7 | Apr 18 – May 2 | Jul 23 – Aug 6 |
| Garlic | – | – | Aug 20 – Sep 10 |
| Warm-season crops | |||
| Tomatoes | Apr 6 – 20 | Jun 1 – 15 | – |
| Peppers | Mar 30 – Apr 13 | Jun 8 – 22 | – |
| Cucumbers | – | Jun 1 – 22 | – |
| Zucchini | – | Jun 1 – 29 | – |
| Pumpkins | – | Jun 1 – 22 | – |
| Green beans | – | Jun 1 – Jul 23 | – |
| Sweet corn | – | Jun 1 – 29 | – |
| Basil | Apr 27 – May 11 | Jun 8 – 15 | – |
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 1 | May 16 | May 2 |
| Fall frost before | September 17 | October 1 | October 15 |
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 5 (May 20 in a late year), and the first one in fall around October 11.
Where these dates come from
NOAA weather station ROXBOROUGH SP, CO US (USC00057249), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 5 miles:
80131
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.