When to plant in Challis, ID
Planting dates worked out from Challis's own frost records, not a generic zone chart.
Safe to plant out
May 29
1 year in 10 has a later frost
Average last frost
May 15
about a 50% chance of a later one
Average first fall frost
Sep 26
1 year in 10 by Sep 11
Frost-free days
132
median, 1991–2020
Station used: Challis Idaho · 0.7 km away · station 1600 m, town 1601 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 | Apr 3 – Apr 17 | May 29 – Jun 12 | Jul 23 |
| Sweet pepper | Mar 20 – Apr 3 | May 29 – Jun 12 | Jul 28 |
| Lettuce (leaf) | Mar 13 – Mar 20 | Apr 17 – May 1 | May 27 |
| Peas | — | Apr 6 – May 4 | May 31 |
| Bush beans | — | May 22 – Jun 12 | Jul 11 |
| Carrot | — | Apr 24 – Jun 5 | Jun 23 |
| Beet | — | Apr 20 – Jun 1 | Jun 9 |
| Potato | — | Apr 24 – May 15 | Jul 3 |
| Kale | Mar 6 – Mar 20 | Apr 17 – May 1 | May 30 |
| Broccoli | Mar 6 – Mar 20 | Apr 17 – May 8 | Jun 16 |
| Cucumber | May 1 – May 8 | May 29 – Jun 12 | Jul 18 |
| Summer squash and zucchini | May 1 – May 8 | May 29 – Jun 12 | Jul 13 |
| Winter squash | May 1 – May 8 | May 29 – Jun 12 | Aug 17 |
| Sweet corn | — | May 22 – Jun 12 | Jul 21 |
| Onion (from sets) | — | Apr 17 – May 8 | Jul 16 |
| Garlic | — | Sep 12 – Oct 10 (fall) | following summer |
| Spinach | — | Apr 6 – May 4 | May 14 |
| Basil | Apr 17 – May 1 | May 29 – Jun 12 | Jul 25 |
Challis'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 |
|---|---|
| 1997 | May 2 |
| 1998 | May 28 |
| 1999 | Jun 9 |
| 2000 | May 12 |
| 2001 | Jun 13 |
| 2003 | May 20 |
| 2004 | May 29 |
| 2005 | May 1 |
| 2007 | May 22 |
| 2008 | May 13 |
| 2009 | May 13 |
| 2010 | May 23 |
| 2011 | May 17 |
| 2012 | May 11 |
| 2014 | May 13 |
| 2015 | Apr 27 |
| 2016 | May 11 |
| 2017 | May 14 |
| 2018 | Apr 25 |
| 2019 | May 3 |
| 2020 | May 16 |
| 2021 | May 11 |
| 2022 | May 23 |
| 2023 | May 8 |
| 2024 | May 24 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1997 | 156 |
| 1998 | 128 |
| 1999 | 108 |
| 2000 | 132 |
| 2001 | 113 |
| 2003 | 115 |
| 2004 | 114 |
| 2005 | 132 |
| 2007 | 125 |
| 2008 | 111 |
| 2009 | 140 |
| 2010 | 105 |
| 2011 | 144 |
| 2012 | 144 |
| 2014 | 121 |
| 2015 | 178 |
| 2016 | 124 |
| 2017 | 133 |
| 2018 | 165 |
| 2019 | 148 |
| 2020 | 151 |
| 2021 | 140 |
| 2022 | 145 |
| 2023 | 170 |
| 2024 | 146 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1997 | 15.3 °C |
| 1998 | 15.8 °C |
| 1999 | 14.9 °C |
| 2000 | 16.4 °C |
| 2001 | 16.1 °C |
| 2003 | 16.7 °C |
| 2004 | 15.6 °C |
| 2005 | 15.1 °C |
| 2007 | 16.6 °C |
| 2008 | 15.2 °C |
| 2009 | 15.8 °C |
| 2010 | 14.1 °C |
| 2011 | 14.8 °C |
| 2012 | 16.4 °C |
| 2014 | 15.7 °C |
| 2015 | 16.0 °C |
| 2016 | 16.1 °C |
| 2017 | 15.9 °C |
| 2018 | 16.3 °C |
| 2019 | 15.5 °C |
| 2020 | 15.7 °C |
| 2021 | 16.8 °C |
| 2022 | 15.5 °C |
| 2023 | 15.4 °C |
| 2024 | 16.2 °C |
What this means for you: This station's record is too short to show a reliable trend yet.
Source: daily records from Challis Idaho (NOAA GHCN-Daily). Years with too many missing days are left out.