Idalia, CO frost dates
Last spring frostMay 4median date
First fall frostOct 9median date
Growing season158 daysfrost-free
Hardiness zone6aZone 6a
How Idalia compares
- In 8 years out of 10, the last spring frost in Idalia falls between April 21 and May 17, a 26-day window. The first fall frost falls between September 24 and October 20.
- The median last frost is 7 days earlier than the Colorado median of May 11.
- Its 158-day growing season is longer than 73% of the 374 Colorado places with a regular frost season (state median 146 days).
- The last frost is 5 days later than the zone 6a median of Apr 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6a chart.
- The weather station records an average of 163 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 21 |
| 50% (median) | May 4 |
| 10% (safe for tender plants) | May 17 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 24 |
| 50% (median) | October 9 |
| 90% (late) | October 20 |
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 Idalia, CO
Idalia, CO frost dates — last frost May 4, first frost Oct 9, zone 6a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Feb 9 to Feb 23Transplant outside: Apr 6 to Apr 20
Start indoors: Feb 23 to Mar 9Transplant outside: May 18 to Jun 1
Start indoors: Feb 23 to Mar 9Transplant outside: May 18 to Jun 1
Start indoors: Mar 9 to Mar 23Transplant outside: May 11 to May 25
Start indoors: Mar 9 to Mar 23Transplant outside: Apr 13 to Apr 27Sow outdoors: Apr 6 to May 11Plant for fall: Aug 14 to Sep 11
Start indoors: Mar 9 to Mar 23Transplant outside: Apr 6 to Apr 20Sow outdoors: Apr 6 to Apr 20Plant for fall: Jul 31 to Aug 21
Start indoors: Mar 9 to Mar 23Transplant outside: Apr 20 to May 4Plant for fall: Jul 3 to Jul 24
Start indoors: Mar 9 to Mar 23Transplant outside: Apr 13 to Apr 27Plant for fall: Jul 3 to Jul 24
Start indoors: Mar 9 to Mar 23Transplant outside: Apr 20 to May 4Plant for fall: Jul 3 to Jul 24
Start indoors: Mar 23 to Apr 6Transplant outside: May 25 to Jun 8Sow outdoors: May 25 to Jun 8
Start indoors: Mar 23 to Apr 6Transplant outside: May 11 to May 25
Sow outdoors: Mar 23 to Apr 13Plant for fall: Jul 17 to Aug 7
Sow outdoors: Mar 23 to Apr 13Plant for fall: Aug 14 to Sep 4
Sow outdoors: Mar 30 to May 11Plant for fall: Aug 28 to Sep 18
Start indoors: Apr 6 to Apr 13Transplant outside: May 18 to May 25Sow outdoors: May 11 to May 25Plant for fall: Jul 24 to Aug 7
Start indoors: Apr 6 to Apr 13Sow outdoors: May 11 to May 25Plant for fall: Jul 31 to Aug 14
Start indoors: Apr 6 to Apr 13Sow outdoors: May 11 to May 25
Start indoors: Apr 6 to Apr 13Transplant outside: May 18 to Jun 1
Sow outdoors: Apr 13 to May 11Plant for fall: Jul 17 to Jul 31
Sow outdoors: Apr 13 to May 11Plant for fall: Jul 31 to Aug 14
Sow outdoors: Apr 13 to May 4
Sow outdoors: Apr 20 to May 18Plant for fall: Jul 31 to Aug 14
Sow outdoors: Apr 20 to May 11Plant for fall: Aug 14 to Sep 4
Sow outdoors: May 11 to Jun 1Plant for fall: Jul 24 to Aug 7
Sow outdoors: May 11 to May 25
Transplant outside: May 18 to Jun 8
Plant for fall: Sep 25 to Oct 30
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Idalia, CO
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 9 – Feb 23 | Apr 6 – Apr 20 | — | — |
| Peppers | Feb 23 – Mar 9 | May 18 – Jun 1 | — | — |
| Eggplant | Feb 23 – Mar 9 | May 18 – Jun 1 | — | — |
| Tomatoes | Mar 9 – Mar 23 | May 11 – May 25 | — | — |
| Lettuce | Mar 9 – Mar 23 | Apr 13 – Apr 27 | Apr 6 – May 11 | Aug 14 – Sep 11 |
| Kale | Mar 9 – Mar 23 | Apr 6 – Apr 20 | Apr 6 – Apr 20 | Jul 31 – Aug 21 |
| Broccoli | Mar 9 – Mar 23 | Apr 20 – May 4 | — | Jul 3 – Jul 24 |
| Cabbage | Mar 9 – Mar 23 | Apr 13 – Apr 27 | — | Jul 3 – Jul 24 |
| Cauliflower | Mar 9 – Mar 23 | Apr 20 – May 4 | — | Jul 3 – Jul 24 |
| Okra | Mar 23 – Apr 6 | May 25 – Jun 8 | May 25 – Jun 8 | — |
| Basil | Mar 23 – Apr 6 | May 11 – May 25 | — | — |
| Peas | — | — | Mar 23 – Apr 13 | Jul 17 – Aug 7 |
| Spinach | — | — | Mar 23 – Apr 13 | Aug 14 – Sep 4 |
| Radishes | — | — | Mar 30 – May 11 | Aug 28 – Sep 18 |
| Cucumbers | Apr 6 – Apr 13 | May 18 – May 25 | May 11 – May 25 | Jul 24 – Aug 7 |
| Zucchini & Summer Squash | Apr 6 – Apr 13 | — | May 11 – May 25 | Jul 31 – Aug 14 |
| Winter Squash & Pumpkins | Apr 6 – Apr 13 | — | May 11 – May 25 | — |
| Melons & Watermelon | Apr 6 – Apr 13 | May 18 – Jun 1 | — | — |
| Carrots | — | — | Apr 13 – May 11 | Jul 17 – Jul 31 |
| Beets | — | — | Apr 13 – May 11 | Jul 31 – Aug 14 |
| Potatoes | — | — | Apr 13 – May 4 | — |
| Swiss Chard | — | — | Apr 20 – May 18 | Jul 31 – Aug 14 |
| Cilantro | — | — | Apr 20 – May 11 | Aug 14 – Sep 4 |
| Green Beans | — | — | May 11 – Jun 1 | Jul 24 – Aug 7 |
| Sweet Corn | — | — | May 11 – May 25 | — |
| Sweet Potatoes | — | May 18 – Jun 8 | — | — |
| Garlic | — | — | — | Sep 25 – Oct 30 |
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 Idalia, CO weather station, 17 km away (elevation 3,967 ft (1,209 m)).
Frost dates near Idalia
- Vernon May 7 · Oct 6
- Kirk May 3 · Oct 9
- Joes May 3 · Oct 9
- Wray May 7 · Oct 6
- Eckley May 1 · Oct 12
- Yuma May 1 · Oct 12
- Cope May 3 · Oct 9
- Bethune May 6 · Oct 9
- Burlington May 6 · Oct 9
- Stratton May 6 · Oct 9
Frequently asked questions
When is the last frost in Idalia, CO?
The median last spring frost in Idalia, CO is May 4. There is still about a 10% chance of frost after May 17, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Idalia, CO?
The median first fall frost is October 9, with about a 10% chance of frost before September 24.
How long is the growing season in Idalia, CO?
About 158 days between the median last spring frost and first fall frost.
What planting zone is Idalia, CO?
Idalia, CO is in USDA hardiness zone 6a.