Lewis, CO frost dates
Last spring frostMay 15median date
First fall frostOct 8median date
Growing season146 daysfrost-free
Hardiness zone6bZone 6b
How Lewis compares
- In 8 years out of 10, the last spring frost in Lewis falls between April 30 and May 31, a 31-day window. The first fall frost falls between September 26 and October 22.
- The median last frost is 4 days later than the Colorado median of May 11.
- Its 146-day growing season is longer than 50% of the 374 Colorado places with a regular frost season (state median 146 days).
- The last frost is 23 days later than the zone 6b median of Apr 22. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6b chart.
- The weather station records an average of 160 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 30 |
| 50% (median) | May 15 |
| 10% (safe for tender plants) | May 31 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 26 |
| 50% (median) | October 8 |
| 90% (late) | October 22 |
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 Lewis, CO
Lewis, CO frost dates — last frost May 15, first frost Oct 8, zone 6b. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Feb 20 to Mar 6Transplant outside: Apr 17 to May 1
Start indoors: Mar 6 to Mar 20Transplant outside: May 29 to Jun 12
Start indoors: Mar 6 to Mar 20Transplant outside: May 29 to Jun 12
Start indoors: Mar 20 to Apr 3Transplant outside: May 22 to Jun 5
Start indoors: Mar 20 to Apr 3Transplant outside: Apr 24 to May 8Sow outdoors: Apr 17 to May 22Plant for fall: Aug 13 to Sep 10
Start indoors: Mar 20 to Apr 3Transplant outside: Apr 17 to May 1Sow outdoors: Apr 17 to May 1Plant for fall: Jul 30 to Aug 20
Start indoors: Mar 20 to Apr 3Transplant outside: May 1 to May 15Plant for fall: Jul 2 to Jul 23
Start indoors: Mar 20 to Apr 3Transplant outside: Apr 24 to May 8Plant for fall: Jul 2 to Jul 23
Start indoors: Mar 20 to Apr 3Transplant outside: May 1 to May 15Plant for fall: Jul 2 to Jul 23
Start indoors: Apr 3 to Apr 17Transplant outside: Jun 5 to Jun 19Sow outdoors: Jun 5 to Jun 19
Start indoors: Apr 3 to Apr 17Transplant outside: May 22 to Jun 5
Sow outdoors: Apr 3 to Apr 24Plant for fall: Jul 16 to Aug 6
Sow outdoors: Apr 3 to Apr 24Plant for fall: Aug 13 to Sep 3
Sow outdoors: Apr 10 to May 22Plant for fall: Aug 27 to Sep 17
Start indoors: Apr 17 to Apr 24Transplant outside: May 29 to Jun 5Sow outdoors: May 22 to Jun 5Plant for fall: Jul 23 to Aug 6
Start indoors: Apr 17 to Apr 24Sow outdoors: May 22 to Jun 5Plant for fall: Jul 30 to Aug 13
Start indoors: Apr 17 to Apr 24Sow outdoors: May 22 to Jun 5
Start indoors: Apr 17 to Apr 24Transplant outside: May 29 to Jun 12
Sow outdoors: Apr 24 to May 22Plant for fall: Jul 16 to Jul 30
Sow outdoors: Apr 24 to May 22Plant for fall: Jul 30 to Aug 13
Sow outdoors: Apr 24 to May 15
Sow outdoors: May 1 to May 29Plant for fall: Jul 30 to Aug 13
Sow outdoors: May 1 to May 22Plant for fall: Aug 13 to Sep 3
Sow outdoors: May 22 to Jun 12Plant for fall: Jul 23 to Aug 6
Sow outdoors: May 22 to Jun 5
Transplant outside: May 29 to Jun 19
Plant for fall: Sep 24 to Oct 29
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Lewis, CO
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 20 – Mar 6 | Apr 17 – May 1 | — | — |
| Peppers | Mar 6 – Mar 20 | May 29 – Jun 12 | — | — |
| Eggplant | Mar 6 – Mar 20 | May 29 – Jun 12 | — | — |
| Tomatoes | Mar 20 – Apr 3 | May 22 – Jun 5 | — | — |
| Lettuce | Mar 20 – Apr 3 | Apr 24 – May 8 | Apr 17 – May 22 | Aug 13 – Sep 10 |
| Kale | Mar 20 – Apr 3 | Apr 17 – May 1 | Apr 17 – May 1 | Jul 30 – Aug 20 |
| Broccoli | Mar 20 – Apr 3 | May 1 – May 15 | — | Jul 2 – Jul 23 |
| Cabbage | Mar 20 – Apr 3 | Apr 24 – May 8 | — | Jul 2 – Jul 23 |
| Cauliflower | Mar 20 – Apr 3 | May 1 – May 15 | — | Jul 2 – Jul 23 |
| Okra | Apr 3 – Apr 17 | Jun 5 – Jun 19 | Jun 5 – Jun 19 | — |
| Basil | Apr 3 – Apr 17 | May 22 – Jun 5 | — | — |
| Peas | — | — | Apr 3 – Apr 24 | Jul 16 – Aug 6 |
| Spinach | — | — | Apr 3 – Apr 24 | Aug 13 – Sep 3 |
| Radishes | — | — | Apr 10 – May 22 | Aug 27 – Sep 17 |
| Cucumbers | Apr 17 – Apr 24 | May 29 – Jun 5 | May 22 – Jun 5 | Jul 23 – Aug 6 |
| Zucchini & Summer Squash | Apr 17 – Apr 24 | — | May 22 – Jun 5 | Jul 30 – Aug 13 |
| Winter Squash & Pumpkins | Apr 17 – Apr 24 | — | May 22 – Jun 5 | — |
| Melons & Watermelon | Apr 17 – Apr 24 | May 29 – Jun 12 | — | — |
| Carrots | — | — | Apr 24 – May 22 | Jul 16 – Jul 30 |
| Beets | — | — | Apr 24 – May 22 | Jul 30 – Aug 13 |
| Potatoes | — | — | Apr 24 – May 15 | — |
| Swiss Chard | — | — | May 1 – May 29 | Jul 30 – Aug 13 |
| Cilantro | — | — | May 1 – May 22 | Aug 13 – Sep 3 |
| Green Beans | — | — | May 22 – Jun 12 | Jul 23 – Aug 6 |
| Sweet Corn | — | — | May 22 – Jun 5 | — |
| Sweet Potatoes | — | May 29 – Jun 19 | — | — |
| Garlic | — | — | — | Sep 24 – Oct 29 |
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 Yellow Jacket 4ne, CO weather station, 5 km away (elevation 7,090 ft (2,161 m)).
Frost dates near Lewis
- Yellow Jacket May 17 · Oct 9
- Pleasant View May 17 · Oct 9
- Dolores May 12 · Oct 7
- Cortez May 12 · Oct 7
- Cahone May 11 · Oct 12
- Towaoc May 27 · Sep 28
- Mesa Verde National Park May 6 · Oct 14
- Dove Creek May 11 · Oct 12
- Mancos Jun 4 · Sep 24
- Egnar Jun 3 · Sep 25
Frequently asked questions
When is the last frost in Lewis, CO?
The median last spring frost in Lewis, CO is May 15. 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 Lewis, CO?
The median first fall frost is October 8, with about a 10% chance of frost before September 26.
How long is the growing season in Lewis, CO?
About 146 days between the median last spring frost and first fall frost.
What planting zone is Lewis, CO?
Lewis, CO is in USDA hardiness zone 6b.