Hayden, CO frost dates
Last spring frostJun 1median date
First fall frostSep 20median date
Growing season111 daysfrost-free
Hardiness zone5aZone 5a
How Hayden compares
- In 8 years out of 10, the last spring frost in Hayden falls between May 15 and June 16, a 32-day window. The first fall frost falls between September 7 and September 30.
- The median last frost is 21 days later than the Colorado median of May 11.
- Its 111-day growing season is longer than 19% of the 374 Colorado places with a regular frost season (state median 146 days).
- The last frost is 29 days later than the zone 5a median of May 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5a chart.
- The weather station records an average of 197 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 15 |
| 50% (median) | June 1 |
| 10% (safe for tender plants) | June 16 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 7 |
| 50% (median) | September 20 |
| 90% (late) | September 30 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Hayden, CO
Hayden, CO frost dates — last frost Jun 1, first frost Sep 20, zone 5a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Mar 9 to Mar 23Transplant outside: May 4 to May 18
Start indoors: Mar 23 to Apr 6Transplant outside: Jun 15 to Jun 29
Start indoors: Mar 23 to Apr 6Transplant outside: Jun 15 to Jun 29
Start indoors: Apr 6 to Apr 20Transplant outside: Jun 8 to Jun 22
Start indoors: Apr 6 to Apr 20Transplant outside: May 11 to May 25Sow outdoors: May 4 to Jun 8Plant for fall: Jul 26 to Aug 23
Start indoors: Apr 6 to Apr 20Transplant outside: May 4 to May 18Sow outdoors: May 4 to May 18Plant for fall: Jul 12 to Aug 2
Start indoors: Apr 6 to Apr 20Transplant outside: May 18 to Jun 1
Start indoors: Apr 6 to Apr 20Transplant outside: May 11 to May 25
Start indoors: Apr 6 to Apr 20Transplant outside: May 18 to Jun 1
Start indoors: Apr 20 to May 4Transplant outside: Jun 22 to Jul 6Sow outdoors: Jun 22 to Jul 6
Start indoors: Apr 20 to May 4Transplant outside: Jun 8 to Jun 22
Sow outdoors: Apr 20 to May 11Plant for fall: Jun 28 to Jul 19
Sow outdoors: Apr 20 to May 11Plant for fall: Jul 26 to Aug 16
Sow outdoors: Apr 27 to Jun 8Plant for fall: Aug 9 to Aug 30
Start indoors: May 4 to May 11Transplant outside: Jun 15 to Jun 22Sow outdoors: Jun 8 to Jun 22
Start indoors: May 4 to May 11Sow outdoors: Jun 8 to Jun 22Plant for fall: Jul 12 to Jul 26
Start indoors: May 4 to May 11Sow outdoors: Jun 8 to Jun 22
Start indoors: May 4 to May 11Transplant outside: Jun 15 to Jun 29
Sow outdoors: May 11 to Jun 8Plant for fall: Jun 28 to Jul 12
Sow outdoors: May 11 to Jun 8Plant for fall: Jul 12 to Jul 26
Sow outdoors: May 11 to Jun 1
Sow outdoors: May 18 to Jun 15Plant for fall: Jul 12 to Jul 26
Sow outdoors: May 18 to Jun 8Plant for fall: Jul 26 to Aug 16
Sow outdoors: Jun 8 to Jun 29
Sow outdoors: Jun 8 to Jun 22
Transplant outside: Jun 15 to Jul 6
Plant for fall: Sep 6 to Oct 11
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Hayden, CO
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 9 – Mar 23 | May 4 – May 18 | — | — |
| Peppers | Mar 23 – Apr 6 | Jun 15 – Jun 29 | — | — |
| Eggplant | Mar 23 – Apr 6 | Jun 15 – Jun 29 | — | — |
| Tomatoes | Apr 6 – Apr 20 | Jun 8 – Jun 22 | — | — |
| Lettuce | Apr 6 – Apr 20 | May 11 – May 25 | May 4 – Jun 8 | Jul 26 – Aug 23 |
| Kale | Apr 6 – Apr 20 | May 4 – May 18 | May 4 – May 18 | Jul 12 – Aug 2 |
| Broccoli | Apr 6 – Apr 20 | May 18 – Jun 1 | — | — |
| Cabbage | Apr 6 – Apr 20 | May 11 – May 25 | — | — |
| Cauliflower | Apr 6 – Apr 20 | May 18 – Jun 1 | — | — |
| Okra | Apr 20 – May 4 | Jun 22 – Jul 6 | Jun 22 – Jul 6 | — |
| Basil | Apr 20 – May 4 | Jun 8 – Jun 22 | — | — |
| Peas | — | — | Apr 20 – May 11 | Jun 28 – Jul 19 |
| Spinach | — | — | Apr 20 – May 11 | Jul 26 – Aug 16 |
| Radishes | — | — | Apr 27 – Jun 8 | Aug 9 – Aug 30 |
| Cucumbers | May 4 – May 11 | Jun 15 – Jun 22 | Jun 8 – Jun 22 | — |
| Zucchini & Summer Squash | May 4 – May 11 | — | Jun 8 – Jun 22 | Jul 12 – Jul 26 |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 111 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 4 – May 11 | — | Jun 8 – Jun 22 | — |
| Melons & Watermelon | May 4 – May 11 | Jun 15 – Jun 29 | — | — |
| Carrots | — | — | May 11 – Jun 8 | Jun 28 – Jul 12 |
| Beets | — | — | May 11 – Jun 8 | Jul 12 – Jul 26 |
| Potatoes | — | — | May 11 – Jun 1 | — |
| Swiss Chard | — | — | May 18 – Jun 15 | Jul 12 – Jul 26 |
| Cilantro | — | — | May 18 – Jun 8 | Jul 26 – Aug 16 |
| Green Beans | — | — | Jun 8 – Jun 29 | — |
| Sweet Corn | — | — | Jun 8 – Jun 22 | — |
| Sweet Potatoes Warning: Your frost-free season is about 111 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 15 – Jul 6 | — | — |
| Garlic | — | — | — | Sep 6 – Oct 11 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Hayden, CO weather station, about 1 km away (elevation 6,467 ft (1,971 m)).
Frost dates near Hayden
- Craig Jun 6 · Sep 12
- Hamilton May 29 · Sep 20
- Steamboat Springs Jun 9 · Sep 12
- Oak Creek Jun 14 · Sep 11
- Clark Jun 9 · Sep 12
- Phippsburg Jun 14 · Sep 11
- Yampa Jun 14 · Sep 11
- Slater Jun 1 · Sep 18
- Coalmont frost any month
- Toponas Jun 14 · Sep 11
Frequently asked questions
When is the last frost in Hayden, CO?
The median last spring frost in Hayden, CO is June 1. There is still about a 10% chance of frost after June 16, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Hayden, CO?
The median first fall frost is September 20, with about a 10% chance of frost before September 7.
How long is the growing season in Hayden, CO?
About 111 days between the median last spring frost and first fall frost.
What planting zone is Hayden, CO?
Hayden, CO is in USDA hardiness zone 5a.