Glen Haven, CO frost dates
Last spring frostMay 30median date
First fall frostSep 17median date
Growing season110 daysfrost-free
Hardiness zone5bZone 5b
How Glen Haven compares
- In 8 years out of 10, the last spring frost in Glen Haven falls between May 15 and June 14, a 30-day window. The first fall frost falls between September 3 and October 1.
- The median last frost is 19 days later than the Colorado median of May 11.
- Its 110-day growing season is longer than 17% 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 184 nights a year at or below 32°F.
- Compared with Loveland, CO, 31 km away, the last frost here is 20 days later than there and the growing season is 34 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 15 |
| 50% (median) | May 30 |
| 10% (safe for tender plants) | June 14 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 3 |
| 50% (median) | September 17 |
| 90% (late) | October 1 |
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 Glen Haven, CO
Glen Haven, CO frost dates — last frost May 30, first frost Sep 17, 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 23 to Aug 20
Start indoors: Apr 4 to Apr 18Transplant outside: May 2 to May 16Sow outdoors: May 2 to May 16Plant for fall: Jul 9 to Jul 30
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 25 to Jul 16
Sow outdoors: Apr 18 to May 9Plant for fall: Jul 23 to Aug 13
Sow outdoors: Apr 25 to Jun 6Plant for fall: Aug 6 to Aug 27
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 9 to Jul 23
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 25 to Jul 9
Sow outdoors: May 9 to Jun 6Plant for fall: Jul 9 to Jul 23
Sow outdoors: May 9 to May 30
Sow outdoors: May 16 to Jun 13Plant for fall: Jul 9 to Jul 23
Sow outdoors: May 16 to Jun 6Plant for fall: Jul 23 to Aug 13
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 3 to Oct 8
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Glen Haven, 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 23 – Aug 20 |
| Kale | Apr 4 – Apr 18 | May 2 – May 16 | May 2 – May 16 | Jul 9 – Jul 30 |
| 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 25 – Jul 16 |
| Spinach | — | — | Apr 18 – May 9 | Jul 23 – Aug 13 |
| Radishes | — | — | Apr 25 – Jun 6 | Aug 6 – Aug 27 |
| 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 9 – Jul 23 |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 110 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 25 – Jul 9 |
| Beets | — | — | May 9 – Jun 6 | Jul 9 – Jul 23 |
| Potatoes | — | — | May 9 – May 30 | — |
| Swiss Chard | — | — | May 16 – Jun 13 | Jul 9 – Jul 23 |
| Cilantro | — | — | May 16 – Jun 6 | Jul 23 – Aug 13 |
| Green Beans | — | — | Jun 6 – Jun 27 | — |
| Sweet Corn | — | — | Jun 6 – Jun 20 | — |
| Sweet Potatoes Warning: Your frost-free season is about 110 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 13 – Jul 4 | — | — |
| Garlic | — | — | — | Sep 3 – Oct 8 |
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 Estes Park 3 Sse, CO weather station, 14 km away (elevation 7,812 ft (2,381 m)).
Frost dates near Glen Haven
- Drake May 30 · Sep 17
- Estes Park (Larimer) May 30 · Sep 17
- Masonville May 12 · Oct 1
- Estes Park frost any month
- Bellvue May 21 · Sep 29
- Allenspark Jun 14 · Sep 12
- Lyons Jun 14 · Sep 12
- Loveland May 10 · Oct 1
- Laporte May 2 · Oct 7
- Berthoud May 7 · Oct 5
Frequently asked questions
When is the last frost in Glen Haven, CO?
The median last spring frost in Glen Haven, 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 Glen Haven, CO?
The median first fall frost is September 17, with about a 10% chance of frost before September 3.
How long is the growing season in Glen Haven, CO?
About 110 days between the median last spring frost and first fall frost.
What planting zone is Glen Haven, CO?
Glen Haven, CO is in USDA hardiness zone 5b.