Frost dates for 80243 — Denver, CO
How Denver compares
- In 8 years out of 10, the last spring frost in Denver falls between April 15 and May 13, a 28-day window. The first fall frost falls between September 28 and October 26.
- The median last frost is 11 days earlier than the Colorado median of May 11.
- Its 165-day growing season is longer than 92% of the 374 Colorado places with a regular frost season (state median 146 days).
- The last frost is typical for zone 6a, where the median is Apr 29.
- The weather station records an average of 150 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 15 |
| 50% (median) | April 30 |
| 10% (safe for tender plants) | May 13 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 28 |
| 50% (median) | October 12 |
| 90% (late) | October 26 |
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 Denver, CO
Frost dates for 80243 — Denver, CO — last frost Apr 30, first frost Oct 12, zone 6a. whenisthelastfrost.com
When to plant vegetables in Denver, CO
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 5 – Feb 19 | Apr 2 – Apr 16 | — | — |
| Peppers | Feb 19 – Mar 5 | May 14 – May 28 | — | — |
| Eggplant | Feb 19 – Mar 5 | May 14 – May 28 | — | — |
| Tomatoes | Mar 5 – Mar 19 | May 7 – May 21 | — | — |
| Lettuce | Mar 5 – Mar 19 | Apr 9 – Apr 23 | Apr 2 – May 7 | Aug 17 – Sep 14 |
| Kale | Mar 5 – Mar 19 | Apr 2 – Apr 16 | Apr 2 – Apr 16 | Aug 3 – Aug 24 |
| Broccoli | Mar 5 – Mar 19 | Apr 16 – Apr 30 | — | Jul 6 – Jul 27 |
| Cabbage | Mar 5 – Mar 19 | Apr 9 – Apr 23 | — | Jul 6 – Jul 27 |
| Cauliflower | Mar 5 – Mar 19 | Apr 16 – Apr 30 | — | Jul 6 – Jul 27 |
| Okra | Mar 19 – Apr 2 | May 21 – Jun 4 | May 21 – Jun 4 | — |
| Basil | Mar 19 – Apr 2 | May 7 – May 21 | — | — |
| Peas | — | — | Mar 19 – Apr 9 | Jul 20 – Aug 10 |
| Spinach | — | — | Mar 19 – Apr 9 | Aug 17 – Sep 7 |
| Radishes | — | — | Mar 26 – May 7 | Aug 31 – Sep 21 |
| Cucumbers | Apr 2 – Apr 9 | May 14 – May 21 | May 7 – May 21 | Jul 27 – Aug 10 |
| Zucchini & Summer Squash | Apr 2 – Apr 9 | — | May 7 – May 21 | Aug 3 – Aug 17 |
| Winter Squash & Pumpkins | Apr 2 – Apr 9 | — | May 7 – May 21 | — |
| Melons & Watermelon | Apr 2 – Apr 9 | May 14 – May 28 | — | — |
| Carrots | — | — | Apr 9 – May 7 | Jul 20 – Aug 3 |
| Beets | — | — | Apr 9 – May 7 | Aug 3 – Aug 17 |
| Potatoes | — | — | Apr 9 – Apr 30 | — |
| Swiss Chard | — | — | Apr 16 – May 14 | Aug 3 – Aug 17 |
| Cilantro | — | — | Apr 16 – May 7 | Aug 17 – Sep 7 |
| Green Beans | — | — | May 7 – May 28 | Jul 27 – Aug 10 |
| Sweet Corn | — | — | May 7 – May 21 | — |
| Sweet Potatoes | — | May 14 – Jun 4 | — | — |
| Garlic | — | — | — | Sep 28 – Nov 2 |
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 Denver Water Dept, CO weather station, 2 km away (elevation 5,230 ft (1,594 m)).
ZIP codes in Denver: 80201 80202 80203 80204 80205 80206 80207 80208 80209 80210 80211 80212 80214 80215 80216 80217 80218 80219 80220 80221 80222 80223 80224 80225 80226 80227 80228 80229 80230 80231 80232 80233 80234 80235 80236 80237 80238 80239 80243 80244 80246 80247 80248 80249 80250 80251 80252 80256 80257 80259 80260 80261 80262 80263 80264 80265 80266 80271 80273 80274 …
Frost dates near Denver
- Wheat Ridge May 5 · Oct 5
- Commerce City May 4 · Oct 8
- Englewood May 2 · Oct 11
- Westminster May 2 · Oct 11
- Dupont May 4 · Oct 8
- Arvada May 5 · Oct 5
- Thornton May 2 · Oct 11
- Aurora May 7 · Oct 8
Frequently asked questions
When is the last frost in Denver, CO?
The median last spring frost in Denver, CO is April 30. There is still about a 10% chance of frost after May 13, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Denver, CO?
The median first fall frost is October 12, with about a 10% chance of frost before September 28.
How long is the growing season in Denver, CO?
About 165 days between the median last spring frost and first fall frost.
What planting zone is Denver, CO?
Denver, CO is in USDA hardiness zone 6a.