Frost dates for Blue River, 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 16
typical year
Safe to plant
June 30
frost is over in 9 of 10 years
First fall frost
September 9
typical year
Growing season
83 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 19 – Jun 2 | – |
| Spinach | – | May 5 – 26 | Jul 15 – 29 |
| Lettuce | – | May 19 – Jun 9 | Jul 15 – 29 |
| Radishes | – | May 19 – Jun 30 | Jul 29 – Aug 12 |
| Onions | – | May 19 – Jun 2 | – |
| Potatoes | Season usually too short. Try a quick variety or row covers. | ||
| Carrots | – | May 26 – Jun 16 | Jun 17 – Jul 1 |
| Beets | – | May 19 – Jun 2 | Jul 1 – 15 |
| Kale | Apr 7 – 21 | May 19 – Jun 2 | Jul 1 – 15 |
| Broccoli | Apr 7 – 21 | Jun 2 – 16 | Jul 1 – 15 |
| Cabbage | Mar 24 – Apr 7 | May 19 – Jun 2 | Jul 1 – 15 |
| Garlic | – | – | Jul 29 – Aug 19 |
| Warm-season crops | |||
| Tomatoes | Season usually too short. Try a quick variety or row covers. | ||
| Peppers | Season usually too short. Try a quick variety or row covers. | ||
| Cucumbers | – | Jun 30 – Jul 21 | – |
| Zucchini | – | Jun 30 – Jul 28 | – |
| Pumpkins | Season usually too short. Try a quick variety or row covers. | ||
| Green beans | – | Jun 30 – Jul 1 | – |
| Sweet corn | Season usually too short. Try a quick variety or row covers. | ||
| Basil | May 26 – Jun 9 | Jul 7 – 14 | – |
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 30 | June 16 | June 2 |
| Fall frost before | August 21 | September 9 | September 24 |
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 June 2 (June 17 in a late year), and the first one in fall around September 21.
Towns that use these dates
This is the nearest NOAA station with frost records for 3 towns.
Blue River, Fairplay, Alma
Where these dates come from
NOAA weather station FAIRPLAY S PARK RD, CO US (USC00052816), 1991–2020 climate normals. It's the nearest station for 4 zip codes, all within 17 miles:
80420, 80424, 80432, 80440
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.