Frost dates for 80215 — Denver, CO
How Denver compares
- In 8 years out of 10, the last spring frost in Denver falls between April 19 and May 18, a 29-day window. The first fall frost falls between September 24 and October 21.
- The median last frost is 8 days earlier than the Colorado median of May 11.
- Its 157-day growing season is longer than 69% of the 374 Colorado places with a regular frost season (state median 146 days).
- The last frost is 4 days later than the zone 6a median of Apr 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6a chart.
- The weather station records an average of 154 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 19 |
| 50% (median) | May 3 |
| 10% (safe for tender plants) | May 18 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 24 |
| 50% (median) | October 7 |
| 90% (late) | October 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 Denver, CO
Frost dates for 80215 — Denver, CO — last frost May 3, first frost Oct 7, zone 6a. whenisthelastfrost.com
When to plant vegetables in Denver, CO
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 8 – Feb 22 | Apr 5 – Apr 19 | — | — |
| Peppers | Feb 22 – Mar 8 | May 17 – May 31 | — | — |
| Eggplant | Feb 22 – Mar 8 | May 17 – May 31 | — | — |
| Tomatoes | Mar 8 – Mar 22 | May 10 – May 24 | — | — |
| Lettuce | Mar 8 – Mar 22 | Apr 12 – Apr 26 | Apr 5 – May 10 | Aug 12 – Sep 9 |
| Kale | Mar 8 – Mar 22 | Apr 5 – Apr 19 | Apr 5 – Apr 19 | Jul 29 – Aug 19 |
| Broccoli | Mar 8 – Mar 22 | Apr 19 – May 3 | — | Jul 1 – Jul 22 |
| Cabbage | Mar 8 – Mar 22 | Apr 12 – Apr 26 | — | Jul 1 – Jul 22 |
| Cauliflower | Mar 8 – Mar 22 | Apr 19 – May 3 | — | Jul 1 – Jul 22 |
| Okra | Mar 22 – Apr 5 | May 24 – Jun 7 | May 24 – Jun 7 | — |
| Basil | Mar 22 – Apr 5 | May 10 – May 24 | — | — |
| Peas | — | — | Mar 22 – Apr 12 | Jul 15 – Aug 5 |
| Spinach | — | — | Mar 22 – Apr 12 | Aug 12 – Sep 2 |
| Radishes | — | — | Mar 29 – May 10 | Aug 26 – Sep 16 |
| Cucumbers | Apr 5 – Apr 12 | May 17 – May 24 | May 10 – May 24 | Jul 22 – Aug 5 |
| Zucchini & Summer Squash | Apr 5 – Apr 12 | — | May 10 – May 24 | Jul 29 – Aug 12 |
| Winter Squash & Pumpkins | Apr 5 – Apr 12 | — | May 10 – May 24 | — |
| Melons & Watermelon | Apr 5 – Apr 12 | May 17 – May 31 | — | — |
| Carrots | — | — | Apr 12 – May 10 | Jul 15 – Jul 29 |
| Beets | — | — | Apr 12 – May 10 | Jul 29 – Aug 12 |
| Potatoes | — | — | Apr 12 – May 3 | — |
| Swiss Chard | — | — | Apr 19 – May 17 | Jul 29 – Aug 12 |
| Cilantro | — | — | Apr 19 – May 10 | Aug 12 – Sep 2 |
| Green Beans | — | — | May 10 – May 31 | Jul 22 – Aug 5 |
| Sweet Corn | — | — | May 10 – May 24 | — |
| Sweet Potatoes | — | May 17 – Jun 7 | — | — |
| Garlic | — | — | — | Sep 23 – Oct 28 |
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 Lakewood, CO weather station, 2 km away (elevation 5,640 ft (1,719 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
- Arvada May 5 · Oct 5
- Golden May 3 · Oct 7
- Westminster May 2 · Oct 11
- Idledale May 23 · Sep 22
- Morrison May 2 · Oct 11
- Englewood May 2 · Oct 11
- Commerce City May 4 · Oct 8
Frequently asked questions
When is the last frost in Denver, CO?
The median last spring frost in Denver, CO is May 3. There is still about a 10% chance of frost after May 18, 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 7, with about a 10% chance of frost before September 24.
How long is the growing season in Denver, CO?
About 157 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.