Dumont, CO frost dates
Last spring frostMay 30median date
First fall frostSep 19median date
Growing season112 daysfrost-free
Hardiness zone5bZone 5b
How Dumont compares
- In 8 years out of 10, the last spring frost in Dumont falls between May 17 and June 14, a 28-day window. The first fall frost falls between September 5 and September 30.
- The median last frost is 19 days later than the Colorado median of May 11.
- Its 112-day growing season is longer than 19% of the 374 Colorado places with a regular frost season (state median 146 days).
- The last frost is 29 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 210 nights a year at or below 32°F.
- Compared with Boulder, CO, 40 km away, the last frost here is 24 days later than there and the growing season is 40 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 17 |
| 50% (median) | May 30 |
| 10% (safe for tender plants) | June 14 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 5 |
| 50% (median) | September 19 |
| 90% (late) | September 30 |
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 Dumont, CO
Dumont, CO frost dates — last frost May 30, first frost Sep 19, zone 5b. whenisthelastfrost.com
Crop
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Start indoors: Mar 7 to Mar 21Transplant outside: May 2 to May 16
Start indoors: Mar 21 to Apr 4Transplant outside: Jun 13 to Jun 27
Start indoors: Mar 21 to Apr 4Transplant outside: Jun 13 to Jun 27
Start indoors: Apr 4 to Apr 18Transplant outside: Jun 6 to Jun 20
Start indoors: Apr 4 to Apr 18Transplant outside: May 9 to May 23Sow outdoors: May 2 to Jun 6Plant for fall: Jul 25 to Aug 22
Start indoors: Apr 4 to Apr 18Transplant outside: May 2 to May 16Sow outdoors: May 2 to May 16Plant for fall: Jul 11 to Aug 1
Start indoors: Apr 4 to Apr 18Transplant outside: May 16 to May 30
Start indoors: Apr 4 to Apr 18Transplant outside: May 9 to May 23
Start indoors: Apr 4 to Apr 18Transplant outside: May 16 to May 30
Start indoors: Apr 18 to May 2Transplant outside: Jun 20 to Jul 4Sow outdoors: Jun 20 to Jul 4
Start indoors: Apr 18 to May 2Transplant outside: Jun 6 to Jun 20
Sow outdoors: Apr 18 to May 9Plant for fall: Jun 27 to Jul 18
Sow outdoors: Apr 18 to May 9Plant for fall: Jul 25 to Aug 15
Sow outdoors: Apr 25 to Jun 6Plant for fall: Aug 8 to Aug 29
Start indoors: May 2 to May 9Transplant outside: Jun 13 to Jun 20Sow outdoors: Jun 6 to Jun 20
Start indoors: May 2 to May 9Sow outdoors: Jun 6 to Jun 20Plant for fall: Jul 11 to Jul 25
Start indoors: May 2 to May 9Sow outdoors: Jun 6 to Jun 20
Start indoors: May 2 to May 9Transplant outside: Jun 13 to Jun 27
Sow outdoors: May 9 to Jun 6Plant for fall: Jun 27 to Jul 11
Sow outdoors: May 9 to Jun 6Plant for fall: Jul 11 to Jul 25
Sow outdoors: May 9 to May 30
Sow outdoors: May 16 to Jun 13Plant for fall: Jul 11 to Jul 25
Sow outdoors: May 16 to Jun 6Plant for fall: Jul 25 to Aug 15
Sow outdoors: Jun 6 to Jun 27
Sow outdoors: Jun 6 to Jun 20
Transplant outside: Jun 13 to Jul 4
Plant for fall: Sep 5 to Oct 10
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Dumont, CO
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 7 – Mar 21 | May 2 – May 16 | — | — |
| Peppers | Mar 21 – Apr 4 | Jun 13 – Jun 27 | — | — |
| Eggplant | Mar 21 – Apr 4 | Jun 13 – Jun 27 | — | — |
| Tomatoes | Apr 4 – Apr 18 | Jun 6 – Jun 20 | — | — |
| Lettuce | Apr 4 – Apr 18 | May 9 – May 23 | May 2 – Jun 6 | Jul 25 – Aug 22 |
| Kale | Apr 4 – Apr 18 | May 2 – May 16 | May 2 – May 16 | Jul 11 – Aug 1 |
| Broccoli | Apr 4 – Apr 18 | May 16 – May 30 | — | — |
| Cabbage | Apr 4 – Apr 18 | May 9 – May 23 | — | — |
| Cauliflower | Apr 4 – Apr 18 | May 16 – May 30 | — | — |
| Okra | Apr 18 – May 2 | Jun 20 – Jul 4 | Jun 20 – Jul 4 | — |
| Basil | Apr 18 – May 2 | Jun 6 – Jun 20 | — | — |
| Peas | — | — | Apr 18 – May 9 | Jun 27 – Jul 18 |
| Spinach | — | — | Apr 18 – May 9 | Jul 25 – Aug 15 |
| Radishes | — | — | Apr 25 – Jun 6 | Aug 8 – Aug 29 |
| Cucumbers | May 2 – May 9 | Jun 13 – Jun 20 | Jun 6 – Jun 20 | — |
| Zucchini & Summer Squash | May 2 – May 9 | — | Jun 6 – Jun 20 | Jul 11 – Jul 25 |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 112 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 2 – May 9 | — | Jun 6 – Jun 20 | — |
| Melons & Watermelon | May 2 – May 9 | Jun 13 – Jun 27 | — | — |
| Carrots | — | — | May 9 – Jun 6 | Jun 27 – Jul 11 |
| Beets | — | — | May 9 – Jun 6 | Jul 11 – Jul 25 |
| Potatoes | — | — | May 9 – May 30 | — |
| Swiss Chard | — | — | May 16 – Jun 13 | Jul 11 – Jul 25 |
| Cilantro | — | — | May 16 – Jun 6 | Jul 25 – Aug 15 |
| Green Beans | — | — | Jun 6 – Jun 27 | — |
| Sweet Corn | — | — | Jun 6 – Jun 20 | — |
| Sweet Potatoes Warning: Your frost-free season is about 112 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 13 – Jul 4 | — | — |
| Garlic | — | — | — | Sep 5 – Oct 10 |
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 Georgetown, CO weather station, 11 km away (elevation 8,520 ft (2,597 m)).
Frost dates near Dumont
- Idaho Springs May 30 · Sep 19
- Empire May 30 · Sep 19
- Central City Jun 5 · Sep 16
- Georgetown May 30 · Sep 19
- Black Hawk Jun 5 · Sep 16
- Silver Plume May 30 · Sep 19
- Rollinsville Jun 5 · Sep 16
- Winter Park frost any month
- Pinecliffe Jun 5 · Sep 16
- Nederland Jun 21 · Sep 2
Frequently asked questions
When is the last frost in Dumont, CO?
The median last spring frost in Dumont, CO is May 30. There is still about a 10% chance of frost after June 14, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Dumont, CO?
The median first fall frost is September 19, with about a 10% chance of frost before September 5.
How long is the growing season in Dumont, CO?
About 112 days between the median last spring frost and first fall frost.
What planting zone is Dumont, CO?
Dumont, CO is in USDA hardiness zone 5b.