Fleming, CO frost dates
Last spring frostMay 4median date
First fall frostOct 11median date
Growing season160 daysfrost-free
Hardiness zone5bZone 5b
How Fleming compares
- In 8 years out of 10, the last spring frost in Fleming falls between April 21 and May 16, a 25-day window. The first fall frost falls between September 29 and October 20.
- The median last frost is 7 days earlier than the Colorado median of May 11.
- Its 160-day growing season is longer than 83% 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 169 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 16 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 29 |
| 50% (median) | October 11 |
| 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 Fleming, CO
Fleming, CO frost dates — last frost May 4, first frost Oct 11, zone 5b. whenisthelastfrost.com
Crop
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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 16 to Sep 13
Start indoors: Mar 9 to Mar 23Transplant outside: Apr 6 to Apr 20Sow outdoors: Apr 6 to Apr 20Plant for fall: Aug 2 to Aug 23
Start indoors: Mar 9 to Mar 23Transplant outside: Apr 20 to May 4Plant for fall: Jul 5 to Jul 26
Start indoors: Mar 9 to Mar 23Transplant outside: Apr 13 to Apr 27Plant for fall: Jul 5 to Jul 26
Start indoors: Mar 9 to Mar 23Transplant outside: Apr 20 to May 4Plant for fall: Jul 5 to Jul 26
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 19 to Aug 9
Sow outdoors: Mar 23 to Apr 13Plant for fall: Aug 16 to Sep 6
Sow outdoors: Mar 30 to May 11Plant for fall: Aug 30 to Sep 20
Start indoors: Apr 6 to Apr 13Transplant outside: May 18 to May 25Sow outdoors: May 11 to May 25Plant for fall: Jul 26 to Aug 9
Start indoors: Apr 6 to Apr 13Sow outdoors: May 11 to May 25Plant for fall: Aug 2 to Aug 16
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 19 to Aug 2
Sow outdoors: Apr 13 to May 11Plant for fall: Aug 2 to Aug 16
Sow outdoors: Apr 13 to May 4
Sow outdoors: Apr 20 to May 18Plant for fall: Aug 2 to Aug 16
Sow outdoors: Apr 20 to May 11Plant for fall: Aug 16 to Sep 6
Sow outdoors: May 11 to Jun 1Plant for fall: Jul 26 to Aug 9
Sow outdoors: May 11 to May 25
Transplant outside: May 18 to Jun 8
Plant for fall: Sep 27 to Nov 1
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Fleming, 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 16 – Sep 13 |
| Kale | Mar 9 – Mar 23 | Apr 6 – Apr 20 | Apr 6 – Apr 20 | Aug 2 – Aug 23 |
| Broccoli | Mar 9 – Mar 23 | Apr 20 – May 4 | — | Jul 5 – Jul 26 |
| Cabbage | Mar 9 – Mar 23 | Apr 13 – Apr 27 | — | Jul 5 – Jul 26 |
| Cauliflower | Mar 9 – Mar 23 | Apr 20 – May 4 | — | Jul 5 – Jul 26 |
| 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 19 – Aug 9 |
| Spinach | — | — | Mar 23 – Apr 13 | Aug 16 – Sep 6 |
| Radishes | — | — | Mar 30 – May 11 | Aug 30 – Sep 20 |
| Cucumbers | Apr 6 – Apr 13 | May 18 – May 25 | May 11 – May 25 | Jul 26 – Aug 9 |
| Zucchini & Summer Squash | Apr 6 – Apr 13 | — | May 11 – May 25 | Aug 2 – Aug 16 |
| 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 19 – Aug 2 |
| Beets | — | — | Apr 13 – May 11 | Aug 2 – Aug 16 |
| Potatoes | — | — | Apr 13 – May 4 | — |
| Swiss Chard | — | — | Apr 20 – May 18 | Aug 2 – Aug 16 |
| Cilantro | — | — | Apr 20 – May 11 | Aug 16 – Sep 6 |
| Green Beans | — | — | May 11 – Jun 1 | Jul 26 – Aug 9 |
| Sweet Corn | — | — | May 11 – May 25 | — |
| Sweet Potatoes | — | May 18 – Jun 8 | — | — |
| Garlic | — | — | — | Sep 27 – Nov 1 |
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 Fleming 3sw, CO weather station, about 1 km away (elevation 4,255 ft (1,297 m)).
Frost dates near Fleming
- Haxtun May 4 · Oct 11
- Iliff Apr 30 · Oct 9
- Crook May 11 · Oct 4
- Sterling Apr 30 · Oct 9
- Paoli May 11 · Oct 3
- Atwood Apr 30 · Oct 9
- Peetz May 15 · Sep 30
- Sedgwick May 6 · Oct 7
- Otis May 8 · Oct 6
- Holyoke May 11 · Oct 3
Frequently asked questions
When is the last frost in Fleming, CO?
The median last spring frost in Fleming, CO is May 4. There is still about a 10% chance of frost after May 16, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Fleming, CO?
The median first fall frost is October 11, with about a 10% chance of frost before September 29.
How long is the growing season in Fleming, CO?
About 160 days between the median last spring frost and first fall frost.
What planting zone is Fleming, CO?
Fleming, CO is in USDA hardiness zone 5b.