Hot Sulphur Springs, CO frost dates
Last spring frostJun 12median date
First fall frostSep 10median date
Growing season90 daysfrost-free
Hardiness zone5bZone 5b
How Hot Sulphur Springs compares
- In 8 years out of 10, the last spring frost in Hot Sulphur Springs falls between May 31 and June 25, a 25-day window. The first fall frost falls between August 31 and September 21.
- The median last frost is 32 days later than the Colorado median of May 11.
- Its 90-day growing season is longer than 9% of the 374 Colorado places with a regular frost season (state median 146 days).
- The last frost is 42 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 242 nights a year at or below 32°F.
- Compared with Boulder, CO, 65 km away, the last frost here is 37 days later than there and the growing season is 62 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 31 |
| 50% (median) | June 12 |
| 10% (safe for tender plants) | June 25 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 31 |
| 50% (median) | September 10 |
| 90% (late) | September 21 |
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 Hot Sulphur Springs, CO
Hot Sulphur Springs, CO frost dates — last frost Jun 12, first frost Sep 10, zone 5b. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Mar 20 to Apr 3Transplant outside: May 15 to May 29
Start indoors: Apr 3 to Apr 17Transplant outside: Jun 26 to Jul 10
Start indoors: Apr 3 to Apr 17Transplant outside: Jun 26 to Jul 10
Start indoors: Apr 17 to May 1Transplant outside: Jun 19 to Jul 3
Start indoors: Apr 17 to May 1Transplant outside: May 22 to Jun 5Sow outdoors: May 15 to Jun 19Plant for fall: Jul 16 to Aug 13
Start indoors: Apr 17 to May 1Transplant outside: May 15 to May 29Sow outdoors: May 15 to May 29Plant for fall: Jul 2 to Jul 23
Start indoors: Apr 17 to May 1Transplant outside: May 29 to Jun 12
Start indoors: Apr 17 to May 1Transplant outside: May 22 to Jun 5
Start indoors: Apr 17 to May 1Transplant outside: May 29 to Jun 12
Start indoors: May 1 to May 15Transplant outside: Jul 3 to Jul 17Sow outdoors: Jul 3 to Jul 17
Start indoors: May 1 to May 15Transplant outside: Jun 19 to Jul 3
Sow outdoors: May 1 to May 22
Sow outdoors: May 1 to May 22Plant for fall: Jul 16 to Aug 6
Sow outdoors: May 8 to Jun 19Plant for fall: Jul 30 to Aug 20
Start indoors: May 15 to May 22Transplant outside: Jun 26 to Jul 3Sow outdoors: Jun 19 to Jul 3
Start indoors: May 15 to May 22Sow outdoors: Jun 19 to Jul 3
Start indoors: May 15 to May 22Sow outdoors: Jun 19 to Jul 3
Start indoors: May 15 to May 22Transplant outside: Jun 26 to Jul 10
Sow outdoors: May 22 to Jun 19
Sow outdoors: May 22 to Jun 19
Sow outdoors: May 22 to Jun 12
Sow outdoors: May 29 to Jun 26
Sow outdoors: May 29 to Jun 19Plant for fall: Jul 16 to Aug 6
Sow outdoors: Jun 19 to Jul 10
Sow outdoors: Jun 19 to Jul 3
Transplant outside: Jun 26 to Jul 17
Plant for fall: Aug 27 to Oct 1
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Hot Sulphur Springs, CO
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 20 – Apr 3 | May 15 – May 29 | — | — |
| Peppers | Apr 3 – Apr 17 | Jun 26 – Jul 10 | — | — |
| Eggplant | Apr 3 – Apr 17 | Jun 26 – Jul 10 | — | — |
| Tomatoes | Apr 17 – May 1 | Jun 19 – Jul 3 | — | — |
| Lettuce | Apr 17 – May 1 | May 22 – Jun 5 | May 15 – Jun 19 | Jul 16 – Aug 13 |
| Kale | Apr 17 – May 1 | May 15 – May 29 | May 15 – May 29 | Jul 2 – Jul 23 |
| Broccoli | Apr 17 – May 1 | May 29 – Jun 12 | — | — |
| Cabbage | Apr 17 – May 1 | May 22 – Jun 5 | — | — |
| Cauliflower | Apr 17 – May 1 | May 29 – Jun 12 | — | — |
| Okra | May 1 – May 15 | Jul 3 – Jul 17 | Jul 3 – Jul 17 | — |
| Basil | May 1 – May 15 | Jun 19 – Jul 3 | — | — |
| Peas | — | — | May 1 – May 22 | — |
| Spinach | — | — | May 1 – May 22 | Jul 16 – Aug 6 |
| Radishes | — | — | May 8 – Jun 19 | Jul 30 – Aug 20 |
| Cucumbers | May 15 – May 22 | Jun 26 – Jul 3 | Jun 19 – Jul 3 | — |
| Zucchini & Summer Squash | May 15 – May 22 | — | Jun 19 – Jul 3 | — |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 90 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 15 – May 22 | — | Jun 19 – Jul 3 | — |
| Melons & Watermelon Warning: Your frost-free season is about 90 days, which is tight for melons & watermelon (85+ days). Choose early varieties and use transplants or row covers. | May 15 – May 22 | Jun 26 – Jul 10 | — | — |
| Carrots | — | — | May 22 – Jun 19 | — |
| Beets | — | — | May 22 – Jun 19 | — |
| Potatoes | — | — | May 22 – Jun 12 | — |
| Swiss Chard | — | — | May 29 – Jun 26 | — |
| Cilantro | — | — | May 29 – Jun 19 | Jul 16 – Aug 6 |
| Green Beans | — | — | Jun 19 – Jul 10 | — |
| Sweet Corn Warning: Your frost-free season is about 90 days, which is tight for sweet corn (80+ days). Choose early varieties and use transplants or row covers. | — | — | Jun 19 – Jul 3 | — |
| Sweet Potatoes Warning: Your frost-free season is about 90 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 26 – Jul 17 | — | — |
| Garlic | — | — | — | Aug 27 – Oct 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 Williams Fork Dam, CO weather station, 12 km away (elevation 7,618 ft (2,322 m)).
Frost dates near Hot Sulphur Springs
- Granby Jun 13 · Sep 7
- Parshall Jun 12 · Sep 10
- Tabernash frost any month
- Grand Lake frost any month
- Fraser frost any month
- Kremmling Jun 14 · Sep 5
- Winter Park frost any month
- Silverthorne frost any month
- Rand frost any month
- Empire May 30 · Sep 19
Frequently asked questions
When is the last frost in Hot Sulphur Springs, CO?
The median last spring frost in Hot Sulphur Springs, CO is June 12. There is still about a 10% chance of frost after June 25, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Hot Sulphur Springs, CO?
The median first fall frost is September 10, with about a 10% chance of frost before August 31.
How long is the growing season in Hot Sulphur Springs, CO?
About 90 days between the median last spring frost and first fall frost.
What planting zone is Hot Sulphur Springs, CO?
Hot Sulphur Springs, CO is in USDA hardiness zone 5b.