Frost dates for Hayden, 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
June 1
typical year
Safe to plant
June 16
frost is over in 9 of 10 years
First fall frost
September 20
typical year
Growing season
109 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 4 – 18 | – |
| Spinach | – | Apr 20 – May 11 | Jul 26 – Aug 9 |
| Lettuce | – | May 4 – 25 | Jul 26 – Aug 9 |
| Radishes | – | May 4 – Jun 15 | Aug 9 – 23 |
| Onions | – | May 4 – 18 | – |
| Potatoes | – | May 11 – 25 | – |
| Carrots | – | May 11 – Jun 1 | Jun 28 – Jul 12 |
| Beets | – | May 4 – 18 | Jul 12 – 26 |
| Kale | Mar 23 – Apr 6 | May 4 – 18 | Jul 12 – 26 |
| Broccoli | Mar 23 – Apr 6 | May 18 – Jun 1 | Jul 12 – 26 |
| Cabbage | Mar 9 – 23 | May 4 – 18 | Jul 12 – 26 |
| Garlic | – | – | Aug 9 – 30 |
| Warm-season crops | |||
| Tomatoes | Apr 21 – May 5 | Jun 16 – 30 | – |
| Peppers | Apr 14 – 28 | Jun 23 – Jul 7 | – |
| Cucumbers | – | Jun 16 – Jul 7 | – |
| Zucchini | – | Jun 16 – Jul 14 | – |
| Pumpkins | Season usually too short. Try a quick variety or row covers. | ||
| Green beans | – | Jun 16 – Jul 12 | – |
| Sweet corn | – | Jun 16 – Jul 14 | – |
| Basil | May 12 – 26 | Jun 23 – 30 | – |
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 16 | June 1 | May 15 |
| Fall frost before | September 7 | September 20 | September 30 |
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 September 29.
Towns that use these dates
This is the nearest NOAA station with frost records for 1 town.
Hayden
Where these dates come from
NOAA weather station HAYDEN, CO US (USC00053867), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 5 miles:
81639
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.