Cortez, CO frost dates
Last spring frostMay 12median date
First fall frostOct 7median date
Growing season148 daysfrost-free
Hardiness zone7aZone 7a
How Cortez compares
- In 8 years out of 10, the last spring frost in Cortez falls between April 30 and May 31, a 31-day window. The first fall frost falls between September 26 and October 21.
- The median last frost is 1 day later than the Colorado median of May 11.
- Its 148-day growing season is longer than 53% of the 374 Colorado places with a regular frost season (state median 146 days).
- The last frost is 26 days later than the zone 7a median of Apr 16. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 7a chart.
- The weather station records an average of 168 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 30 |
| 50% (median) | May 12 |
| 10% (safe for tender plants) | May 31 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 26 |
| 50% (median) | October 7 |
| 90% (late) | October 21 |
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 Cortez, CO
Cortez, CO frost dates — last frost May 12, first frost Oct 7, zone 7a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Feb 17 to Mar 3Transplant outside: Apr 14 to Apr 28
Start indoors: Mar 3 to Mar 17Transplant outside: May 26 to Jun 9
Start indoors: Mar 3 to Mar 17Transplant outside: May 26 to Jun 9
Start indoors: Mar 17 to Mar 31Transplant outside: May 19 to Jun 2
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 21 to May 5Sow outdoors: Apr 14 to May 19Plant for fall: Aug 12 to Sep 9
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 14 to Apr 28Sow outdoors: Apr 14 to Apr 28Plant for fall: Jul 29 to Aug 19
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 28 to May 12Plant for fall: Jul 1 to Jul 22
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 21 to May 5Plant for fall: Jul 1 to Jul 22
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 28 to May 12Plant for fall: Jul 1 to Jul 22
Start indoors: Mar 31 to Apr 14Transplant outside: Jun 2 to Jun 16Sow outdoors: Jun 2 to Jun 16
Start indoors: Mar 31 to Apr 14Transplant outside: May 19 to Jun 2
Sow outdoors: Mar 31 to Apr 21Plant for fall: Jul 15 to Aug 5
Sow outdoors: Mar 31 to Apr 21Plant for fall: Aug 12 to Sep 2
Sow outdoors: Apr 7 to May 19Plant for fall: Aug 26 to Sep 16
Start indoors: Apr 14 to Apr 21Transplant outside: May 26 to Jun 2Sow outdoors: May 19 to Jun 2Plant for fall: Jul 22 to Aug 5
Start indoors: Apr 14 to Apr 21Sow outdoors: May 19 to Jun 2Plant for fall: Jul 29 to Aug 12
Start indoors: Apr 14 to Apr 21Sow outdoors: May 19 to Jun 2
Start indoors: Apr 14 to Apr 21Transplant outside: May 26 to Jun 9
Sow outdoors: Apr 21 to May 19Plant for fall: Jul 15 to Jul 29
Sow outdoors: Apr 21 to May 19Plant for fall: Jul 29 to Aug 12
Sow outdoors: Apr 21 to May 12
Sow outdoors: Apr 28 to May 26Plant for fall: Jul 29 to Aug 12
Sow outdoors: Apr 28 to May 19Plant for fall: Aug 12 to Sep 2
Sow outdoors: May 19 to Jun 9Plant for fall: Jul 22 to Aug 5
Sow outdoors: May 19 to Jun 2
Transplant outside: May 26 to Jun 16
Plant for fall: Sep 23 to Oct 28
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Cortez, CO
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 17 – Mar 3 | Apr 14 – Apr 28 | — | — |
| Peppers | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Eggplant | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Tomatoes | Mar 17 – Mar 31 | May 19 – Jun 2 | — | — |
| Lettuce | Mar 17 – Mar 31 | Apr 21 – May 5 | Apr 14 – May 19 | Aug 12 – Sep 9 |
| Kale | Mar 17 – Mar 31 | Apr 14 – Apr 28 | Apr 14 – Apr 28 | Jul 29 – Aug 19 |
| Broccoli | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jul 1 – Jul 22 |
| Cabbage | Mar 17 – Mar 31 | Apr 21 – May 5 | — | Jul 1 – Jul 22 |
| Cauliflower | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jul 1 – Jul 22 |
| Okra | Mar 31 – Apr 14 | Jun 2 – Jun 16 | Jun 2 – Jun 16 | — |
| Basil | Mar 31 – Apr 14 | May 19 – Jun 2 | — | — |
| Peas | — | — | Mar 31 – Apr 21 | Jul 15 – Aug 5 |
| Spinach | — | — | Mar 31 – Apr 21 | Aug 12 – Sep 2 |
| Radishes | — | — | Apr 7 – May 19 | Aug 26 – Sep 16 |
| Cucumbers | Apr 14 – Apr 21 | May 26 – Jun 2 | May 19 – Jun 2 | Jul 22 – Aug 5 |
| Zucchini & Summer Squash | Apr 14 – Apr 21 | — | May 19 – Jun 2 | Jul 29 – Aug 12 |
| Winter Squash & Pumpkins | Apr 14 – Apr 21 | — | May 19 – Jun 2 | — |
| Melons & Watermelon | Apr 14 – Apr 21 | May 26 – Jun 9 | — | — |
| Carrots | — | — | Apr 21 – May 19 | Jul 15 – Jul 29 |
| Beets | — | — | Apr 21 – May 19 | Jul 29 – Aug 12 |
| Potatoes | — | — | Apr 21 – May 12 | — |
| Swiss Chard | — | — | Apr 28 – May 26 | Jul 29 – Aug 12 |
| Cilantro | — | — | Apr 28 – May 19 | Aug 12 – Sep 2 |
| Green Beans | — | — | May 19 – Jun 9 | Jul 22 – Aug 5 |
| Sweet Corn | — | — | May 19 – Jun 2 | — |
| Sweet Potatoes | — | May 26 – Jun 16 | — | — |
| Garlic | — | — | — | Sep 23 – Oct 28 |
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 Cortez, CO weather station, 2 km away (elevation 6,168 ft (1,880 m)).
Frost dates near Cortez
- Dolores May 12 · Oct 7
- Mesa Verde National Park May 6 · Oct 14
- Lewis May 15 · Oct 8
- Towaoc May 27 · Sep 28
- Yellow Jacket May 17 · Oct 9
- Mancos Jun 4 · Sep 24
- Pleasant View May 17 · Oct 9
- Cahone May 11 · Oct 12
- Hesperus Jun 1 · Sep 27
- Marvel Jun 1 · Sep 27
Frequently asked questions
When is the last frost in Cortez, CO?
The median last spring frost in Cortez, CO is May 12. There is still about a 10% chance of frost after May 31, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Cortez, CO?
The median first fall frost is October 7, with about a 10% chance of frost before September 26.
How long is the growing season in Cortez, CO?
About 148 days between the median last spring frost and first fall frost.
What planting zone is Cortez, CO?
Cortez, CO is in USDA hardiness zone 7a.