Stoneham, CO frost dates
Last spring frostMay 9median date
First fall frostOct 4median date
Growing season148 daysfrost-free
Hardiness zone5bZone 5b
How Stoneham compares
- In 8 years out of 10, the last spring frost in Stoneham falls between April 29 and May 22, a 23-day window. The first fall frost falls between September 21 and October 16.
- The median last frost is 2 days earlier 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 8 days later than the zone 5b median of May 1. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5b chart.
- The weather station records an average of 176 nights a year at or below 32°F.
- Compared with Greeley, CO, 97 km away, the last frost here is 7 days later than there and the growing season is 11 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 29 |
| 50% (median) | May 9 |
| 10% (safe for tender plants) | May 22 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 21 |
| 50% (median) | October 4 |
| 90% (late) | October 16 |
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 Stoneham, CO
Stoneham, CO frost dates — last frost May 9, first frost Oct 4, zone 5b. whenisthelastfrost.com
Crop
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Start indoors: Feb 14 to Feb 28Transplant outside: Apr 11 to Apr 25
Start indoors: Feb 28 to Mar 14Transplant outside: May 23 to Jun 6
Start indoors: Feb 28 to Mar 14Transplant outside: May 23 to Jun 6
Start indoors: Mar 14 to Mar 28Transplant outside: May 16 to May 30
Start indoors: Mar 14 to Mar 28Transplant outside: Apr 18 to May 2Sow outdoors: Apr 11 to May 16Plant for fall: Aug 9 to Sep 6
Start indoors: Mar 14 to Mar 28Transplant outside: Apr 11 to Apr 25Sow outdoors: Apr 11 to Apr 25Plant for fall: Jul 26 to Aug 16
Start indoors: Mar 14 to Mar 28Transplant outside: Apr 25 to May 9Plant for fall: Jun 28 to Jul 19
Start indoors: Mar 14 to Mar 28Transplant outside: Apr 18 to May 2Plant for fall: Jun 28 to Jul 19
Start indoors: Mar 14 to Mar 28Transplant outside: Apr 25 to May 9Plant for fall: Jun 28 to Jul 19
Start indoors: Mar 28 to Apr 11Transplant outside: May 30 to Jun 13Sow outdoors: May 30 to Jun 13
Start indoors: Mar 28 to Apr 11Transplant outside: May 16 to May 30
Sow outdoors: Mar 28 to Apr 18Plant for fall: Jul 12 to Aug 2
Sow outdoors: Mar 28 to Apr 18Plant for fall: Aug 9 to Aug 30
Sow outdoors: Apr 4 to May 16Plant for fall: Aug 23 to Sep 13
Start indoors: Apr 11 to Apr 18Transplant outside: May 23 to May 30Sow outdoors: May 16 to May 30Plant for fall: Jul 19 to Aug 2
Start indoors: Apr 11 to Apr 18Sow outdoors: May 16 to May 30Plant for fall: Jul 26 to Aug 9
Start indoors: Apr 11 to Apr 18Sow outdoors: May 16 to May 30
Start indoors: Apr 11 to Apr 18Transplant outside: May 23 to Jun 6
Sow outdoors: Apr 18 to May 16Plant for fall: Jul 12 to Jul 26
Sow outdoors: Apr 18 to May 16Plant for fall: Jul 26 to Aug 9
Sow outdoors: Apr 18 to May 9
Sow outdoors: Apr 25 to May 23Plant for fall: Jul 26 to Aug 9
Sow outdoors: Apr 25 to May 16Plant for fall: Aug 9 to Aug 30
Sow outdoors: May 16 to Jun 6Plant for fall: Jul 19 to Aug 2
Sow outdoors: May 16 to May 30
Transplant outside: May 23 to Jun 13
Plant for fall: Sep 20 to Oct 25
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Stoneham, CO
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 14 – Feb 28 | Apr 11 – Apr 25 | — | — |
| Peppers | Feb 28 – Mar 14 | May 23 – Jun 6 | — | — |
| Eggplant | Feb 28 – Mar 14 | May 23 – Jun 6 | — | — |
| Tomatoes | Mar 14 – Mar 28 | May 16 – May 30 | — | — |
| Lettuce | Mar 14 – Mar 28 | Apr 18 – May 2 | Apr 11 – May 16 | Aug 9 – Sep 6 |
| Kale | Mar 14 – Mar 28 | Apr 11 – Apr 25 | Apr 11 – Apr 25 | Jul 26 – Aug 16 |
| Broccoli | Mar 14 – Mar 28 | Apr 25 – May 9 | — | Jun 28 – Jul 19 |
| Cabbage | Mar 14 – Mar 28 | Apr 18 – May 2 | — | Jun 28 – Jul 19 |
| Cauliflower | Mar 14 – Mar 28 | Apr 25 – May 9 | — | Jun 28 – Jul 19 |
| Okra | Mar 28 – Apr 11 | May 30 – Jun 13 | May 30 – Jun 13 | — |
| Basil | Mar 28 – Apr 11 | May 16 – May 30 | — | — |
| Peas | — | — | Mar 28 – Apr 18 | Jul 12 – Aug 2 |
| Spinach | — | — | Mar 28 – Apr 18 | Aug 9 – Aug 30 |
| Radishes | — | — | Apr 4 – May 16 | Aug 23 – Sep 13 |
| Cucumbers | Apr 11 – Apr 18 | May 23 – May 30 | May 16 – May 30 | Jul 19 – Aug 2 |
| Zucchini & Summer Squash | Apr 11 – Apr 18 | — | May 16 – May 30 | Jul 26 – Aug 9 |
| Winter Squash & Pumpkins | Apr 11 – Apr 18 | — | May 16 – May 30 | — |
| Melons & Watermelon | Apr 11 – Apr 18 | May 23 – Jun 6 | — | — |
| Carrots | — | — | Apr 18 – May 16 | Jul 12 – Jul 26 |
| Beets | — | — | Apr 18 – May 16 | Jul 26 – Aug 9 |
| Potatoes | — | — | Apr 18 – May 9 | — |
| Swiss Chard | — | — | Apr 25 – May 23 | Jul 26 – Aug 9 |
| Cilantro | — | — | Apr 25 – May 16 | Aug 9 – Aug 30 |
| Green Beans | — | — | May 16 – Jun 6 | Jul 19 – Aug 2 |
| Sweet Corn | — | — | May 16 – May 30 | — |
| Sweet Potatoes | — | May 23 – Jun 13 | — | — |
| Garlic | — | — | — | Sep 20 – Oct 25 |
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 New Raymer, CO weather station, 20 km away (elevation 4,783 ft (1,458 m)).
Frost dates near Stoneham
- New Raymer May 9 · Oct 4
- Merino Apr 30 · Oct 9
- Padroni Apr 30 · Oct 9
- Sterling Apr 30 · Oct 9
- Atwood Apr 30 · Oct 9
- Hillrose May 15 · Oct 1
- Snyder May 6 · Oct 6
- Weldona May 6 · Oct 6
- Iliff Apr 30 · Oct 9
- Brush May 6 · Oct 6
Frequently asked questions
When is the last frost in Stoneham, CO?
The median last spring frost in Stoneham, CO is May 9. There is still about a 10% chance of frost after May 22, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Stoneham, CO?
The median first fall frost is October 4, with about a 10% chance of frost before September 21.
How long is the growing season in Stoneham, CO?
About 148 days between the median last spring frost and first fall frost.
What planting zone is Stoneham, CO?
Stoneham, CO is in USDA hardiness zone 5b.