Haswell, CO frost dates
Last spring frostApr 30median date
First fall frostOct 13median date
Growing season166 daysfrost-free
Hardiness zone5bZone 5b
How Haswell compares
- In 8 years out of 10, the last spring frost in Haswell falls between April 15 and May 12, a 27-day window. The first fall frost falls between October 1 and October 24.
- The median last frost is 11 days earlier than the Colorado median of May 11.
- Its 166-day growing season is longer than 93% of the 374 Colorado places with a regular frost season (state median 146 days).
- The last frost is typical for zone 5b, where the median is May 1.
- The weather station records an average of 156 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 15 |
| 50% (median) | April 30 |
| 10% (safe for tender plants) | May 12 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 1 |
| 50% (median) | October 13 |
| 90% (late) | October 24 |
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 Haswell, CO
Haswell, CO frost dates — last frost Apr 30, first frost Oct 13, zone 5b. whenisthelastfrost.com
Crop
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Start indoors: Feb 5 to Feb 19Transplant outside: Apr 2 to Apr 16
Start indoors: Feb 19 to Mar 5Transplant outside: May 14 to May 28
Start indoors: Feb 19 to Mar 5Transplant outside: May 14 to May 28
Start indoors: Mar 5 to Mar 19Transplant outside: May 7 to May 21
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 9 to Apr 23Sow outdoors: Apr 2 to May 7Plant for fall: Aug 18 to Sep 15
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 2 to Apr 16Sow outdoors: Apr 2 to Apr 16Plant for fall: Aug 4 to Aug 25
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 16 to Apr 30Plant for fall: Jul 7 to Jul 28
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 9 to Apr 23Plant for fall: Jul 7 to Jul 28
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 16 to Apr 30Plant for fall: Jul 7 to Jul 28
Start indoors: Mar 19 to Apr 2Transplant outside: May 21 to Jun 4Sow outdoors: May 21 to Jun 4
Start indoors: Mar 19 to Apr 2Transplant outside: May 7 to May 21
Sow outdoors: Mar 19 to Apr 9Plant for fall: Jul 21 to Aug 11
Sow outdoors: Mar 19 to Apr 9Plant for fall: Aug 18 to Sep 8
Sow outdoors: Mar 26 to May 7Plant for fall: Sep 1 to Sep 22
Start indoors: Apr 2 to Apr 9Transplant outside: May 14 to May 21Sow outdoors: May 7 to May 21Plant for fall: Jul 28 to Aug 11
Start indoors: Apr 2 to Apr 9Sow outdoors: May 7 to May 21Plant for fall: Aug 4 to Aug 18
Start indoors: Apr 2 to Apr 9Sow outdoors: May 7 to May 21
Start indoors: Apr 2 to Apr 9Transplant outside: May 14 to May 28
Sow outdoors: Apr 9 to May 7Plant for fall: Jul 21 to Aug 4
Sow outdoors: Apr 9 to May 7Plant for fall: Aug 4 to Aug 18
Sow outdoors: Apr 9 to Apr 30
Sow outdoors: Apr 16 to May 14Plant for fall: Aug 4 to Aug 18
Sow outdoors: Apr 16 to May 7Plant for fall: Aug 18 to Sep 8
Sow outdoors: May 7 to May 28Plant for fall: Jul 28 to Aug 11
Sow outdoors: May 7 to May 21
Transplant outside: May 14 to Jun 4
Plant for fall: Sep 29 to Nov 3
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Haswell, CO
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 5 – Feb 19 | Apr 2 – Apr 16 | — | — |
| Peppers | Feb 19 – Mar 5 | May 14 – May 28 | — | — |
| Eggplant | Feb 19 – Mar 5 | May 14 – May 28 | — | — |
| Tomatoes | Mar 5 – Mar 19 | May 7 – May 21 | — | — |
| Lettuce | Mar 5 – Mar 19 | Apr 9 – Apr 23 | Apr 2 – May 7 | Aug 18 – Sep 15 |
| Kale | Mar 5 – Mar 19 | Apr 2 – Apr 16 | Apr 2 – Apr 16 | Aug 4 – Aug 25 |
| Broccoli | Mar 5 – Mar 19 | Apr 16 – Apr 30 | — | Jul 7 – Jul 28 |
| Cabbage | Mar 5 – Mar 19 | Apr 9 – Apr 23 | — | Jul 7 – Jul 28 |
| Cauliflower | Mar 5 – Mar 19 | Apr 16 – Apr 30 | — | Jul 7 – Jul 28 |
| Okra | Mar 19 – Apr 2 | May 21 – Jun 4 | May 21 – Jun 4 | — |
| Basil | Mar 19 – Apr 2 | May 7 – May 21 | — | — |
| Peas | — | — | Mar 19 – Apr 9 | Jul 21 – Aug 11 |
| Spinach | — | — | Mar 19 – Apr 9 | Aug 18 – Sep 8 |
| Radishes | — | — | Mar 26 – May 7 | Sep 1 – Sep 22 |
| Cucumbers | Apr 2 – Apr 9 | May 14 – May 21 | May 7 – May 21 | Jul 28 – Aug 11 |
| Zucchini & Summer Squash | Apr 2 – Apr 9 | — | May 7 – May 21 | Aug 4 – Aug 18 |
| Winter Squash & Pumpkins | Apr 2 – Apr 9 | — | May 7 – May 21 | — |
| Melons & Watermelon | Apr 2 – Apr 9 | May 14 – May 28 | — | — |
| Carrots | — | — | Apr 9 – May 7 | Jul 21 – Aug 4 |
| Beets | — | — | Apr 9 – May 7 | Aug 4 – Aug 18 |
| Potatoes | — | — | Apr 9 – Apr 30 | — |
| Swiss Chard | — | — | Apr 16 – May 14 | Aug 4 – Aug 18 |
| Cilantro | — | — | Apr 16 – May 7 | Aug 18 – Sep 8 |
| Green Beans | — | — | May 7 – May 28 | Jul 28 – Aug 11 |
| Sweet Corn | — | — | May 7 – May 21 | — |
| Sweet Potatoes | — | May 14 – Jun 4 | — | — |
| Garlic | — | — | — | Sep 29 – Nov 3 |
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 Eads, CO weather station, 33 km away (elevation 4,213 ft (1,284 m)).
Frost dates near Haswell
- Arlington May 3 · Oct 7
- Wild Horse May 4 · Oct 8
- Karval May 9 · Oct 6
- Mc Clave Apr 24 · Oct 15
- Kit Carson May 10 · Oct 1
- Cheraw Apr 30 · Oct 10
- Sugar City May 2 · Oct 8
- Wiley May 2 · Oct 7
- Eads Apr 30 · Oct 13
- Fort Lyon Apr 29 · Oct 12
Frequently asked questions
When is the last frost in Haswell, CO?
The median last spring frost in Haswell, CO is April 30. There is still about a 10% chance of frost after May 12, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Haswell, CO?
The median first fall frost is October 13, with about a 10% chance of frost before October 1.
How long is the growing season in Haswell, CO?
About 166 days between the median last spring frost and first fall frost.
What planting zone is Haswell, CO?
Haswell, CO is in USDA hardiness zone 5b.