When to plant in Welby, CO
Planting dates worked out from Welby's own frost records, not a generic zone chart.
Safe to plant out
May 21
1 year in 10 has a later frost
Average last frost
May 5
about a 50% chance of a later one
Average first fall frost
Oct 9
1 year in 10 by Sep 28
Frost-free days
155
median, 1991–2020
Station used: Denver Water Dept · 12.7 km away · station 1593 m, town 1565 m. How we match towns to stations
This season
Plan your garden.
Planting dates for common crops
| Crop | Start indoors | Plant out or sow | Harvest from |
|---|---|---|---|
| Tomato | Mar 26 – Apr 9 | May 21 – Jun 4 | Jul 15 |
| Sweet pepper | Mar 12 – Mar 26 | May 21 – Jun 4 | Jul 20 |
| Lettuce (leaf) | Mar 3 – Mar 10 | Apr 7 – Apr 21 | May 17 |
| Peas | — | Mar 24 – Apr 21 | May 18 |
| Bush beans | — | May 14 – Jun 4 | Jul 3 |
| Carrot | — | Apr 14 – May 26 | Jun 13 |
| Beet | — | Apr 7 – May 19 | May 27 |
| Potato | — | Apr 14 – May 5 | Jun 23 |
| Kale | Feb 24 – Mar 10 | Apr 7 – Apr 21 | May 20 |
| Broccoli | Feb 24 – Mar 10 | Apr 7 – Apr 28 | Jun 6 |
| Cucumber | Apr 23 – Apr 30 | May 21 – Jun 4 | Jul 10 |
| Summer squash and zucchini | Apr 23 – Apr 30 | May 21 – Jun 4 | Jul 5 |
| Winter squash | Apr 23 – Apr 30 | May 21 – Jun 4 | Aug 9 |
| Sweet corn | — | May 14 – Jun 4 | Jul 13 |
| Onion (from sets) | — | Apr 7 – Apr 28 | Jul 6 |
| Garlic | — | Sep 25 – Oct 23 (fall) | following summer |
| Spinach | — | Mar 24 – Apr 21 | May 1 |
| Basil | Apr 9 – Apr 23 | May 21 – Jun 4 | Jul 17 |
Welby's weather over time
How the growing season has shifted here, year by year, from the station's own records.
Each year's last spring frostLong-term trend
See the data as a table
| Year | Last spring frost |
|---|---|
| 1998 | Apr 19 |
| 1999 | Apr 24 |
| 2000 | Apr 17 |
| 2001 | May 21 |
| 2002 | May 24 |
| 2003 | May 12 |
| 2004 | May 3 |
| 2006 | May 11 |
| 2007 | Apr 26 |
| 2008 | May 14 |
| 2009 | Apr 28 |
| 2010 | May 13 |
| 2011 | Apr 19 |
| 2012 | Apr 16 |
| 2013 | May 4 |
| 2014 | May 15 |
| 2015 | May 12 |
| 2016 | May 8 |
| 2017 | May 20 |
| 2018 | Apr 26 |
| 2019 | May 24 |
| 2020 | Apr 18 |
| 2021 | Apr 24 |
| 2022 | May 22 |
| 2023 | Apr 24 |
| 2024 | Apr 28 |
| 2025 | Apr 20 |
| 2026 | May 7 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1998 | 181 |
| 1999 | 157 |
| 2000 | 158 |
| 2001 | 137 |
| 2002 | 143 |
| 2003 | 154 |
| 2004 | 174 |
| 2006 | 150 |
| 2009 | 156 |
| 2010 | 166 |
| 2011 | 182 |
| 2012 | 171 |
| 2013 | 152 |
| 2015 | 164 |
| 2016 | 151 |
| 2017 | 141 |
| 2019 | 138 |
| 2020 | 143 |
| 2021 | 173 |
| 2022 | 154 |
| 2023 | 185 |
| 2024 | 185 |
| 2025 | 181 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1998 | 19.2 °C |
| 1999 | 18.3 °C |
| 2000 | 20.1 °C |
| 2001 | 20.1 °C |
| 2002 | 20.1 °C |
| 2003 | 19.3 °C |
| 2004 | 18.2 °C |
| 2005 | 19.1 °C |
| 2006 | 18.4 °C |
| 2007 | 18.9 °C |
| 2008 | 18.3 °C |
| 2009 | 17.6 °C |
| 2010 | 18.9 °C |
| 2011 | 19.0 °C |
| 2012 | 20.7 °C |
| 2013 | 18.5 °C |
| 2014 | 18.0 °C |
| 2015 | 18.2 °C |
| 2016 | 18.3 °C |
| 2017 | 17.8 °C |
| 2018 | 20.2 °C |
| 2019 | 19.4 °C |
| 2020 | 19.7 °C |
| 2021 | 19.6 °C |
| 2022 | 20.0 °C |
| 2023 | 18.9 °C |
| 2024 | 20.2 °C |
| 2025 | 19.5 °C |
| 2026 | 20.8 °C |
What this means for you: This station's record is too short to show a reliable trend yet.
Source: daily records from Denver Water Dept (NOAA GHCN-Daily). Years with too many missing days are left out.