The median last spring freeze in Durango lands on May 21. That comes from NOAA's 1991-2020 climate normals for the town's own weather station, which sits at 6,761 feet. Median is the honest word, because it means a coin flip: half of all springs still have a freeze on or after that date. If you set out tender seedlings on May 21 because a website said so, you are betting against even odds.
What is the average last frost date in Durango?
May 21 for a freeze of 32°F or colder. NOAA publishes the odds in steps, so you can see how risky each date really is (NOAA NCEI). Each date in the table below is the day on or after which that chance of one more 32°F night remains.
| Chance of another 32°F freeze on or after | Date |
|---|---|
| 90% | May 7 |
| 70% | May 15 |
| 50% (the median) | May 21 |
| 40% | May 25 |
| 20% | June 1 |
| 10% | June 7 |
Look at the 40% row. Memorial Day falls on May 25 this year, and at this station the odds of a 32°F night on or after that date were still 40%. NOAA explains the table layout in its normals file guide, and the station's figures rest on 16 years of records, so treat the dates as a guide and not a guarantee. The 1-in-10 tail stretches all the way to June 7.
When is the first fall frost in Durango?
October 2 is the median first 32°F freeze at the same station, with a 10% chance it has already happened by September 19 and a 90% chance by October 15 (NOAA NCEI). Different cold thresholds give different calendars, and NOAA publishes three that matter to a garden:
| Threshold (low temperature) | Median last spring date | Median first fall date |
|---|---|---|
| 36°F or lower | June 2 | September 25 |
| 32°F or lower | May 21 | October 2 |
| 28°F or lower | May 7 | October 12 |
How long is the growing season in Durango?
About 134 days at the 32°F threshold, counting from the median last freeze to the median first one. NOAA's own range for the season runs from 112 days to 152 days depending on which odds you pick. Use the 36°F row if you want the cautious window for tender plants: that one works out to roughly 113 days.
Is the airport colder than town?
Yes, by about eleven days at the end of spring. NOAA also keeps normals for a second station at Durango-La Plata County Airport, which it lists at about 6,660 feet. There the median last 32°F freeze is June 1, the median first fall freeze is September 27, and the median season is only 116 days (NOAA NCEI). That station also sees a low of 32°F or colder on about 202 days a year, against about 180 at the town station. Which of the two your yard resembles depends on where you live, so a garden near the airport side of the county should plan on the later date.
Our own tally in the first-snow answer counted 18 seasons of the old town station's daily readings and found a median last freeze of May 18, with the extremes running from April 26 to June 18. NOAA's published normal is three days later. Both say the same thing: mid to late May, with real risk after.
When should I plant vegetables, given those dates?
Colorado State University Extension's Master Gardener guide ties each crop group to the average last spring frost (CSU Extension). Applied to a May 21 median, its rules work out like this:
- Hardy crops such as peas, spinach, lettuce and radishes can go in 2 to 4 weeks before the date, roughly April 23 to May 7, as soon as the soil is workable
- Semi-hardy crops such as carrots, beets and potatoes can go in 0 to 2 weeks before, roughly May 7 to May 21
- Tender crops such as beans, corn and cucumbers are sown from seed around the date itself
- Very tender crops such as tomatoes, peppers, eggplant and winter squash typically wait 2 or more weeks after it, so about June 4 or later
That last line is the one that bites at this elevation. A tomato transplant set out on June 4 needs about 65 days to bear, per the same guide, which points to early August. Winter squash needs about 100 days from planting, which runs to September 12 and leaves little slack before the 10% first-freeze date of September 19. You can find starts and row cover at the local garden centers, and the seasonal home maintenance guide has the rest of the yearly calendar. Your hardiness zone is a separate question, covered in our growing zone answer.