When to plant in Shelby, MT
Planting dates worked out from Shelby's own frost records, not a generic zone chart.
Safe to plant out
Jun 12
1 year in 10 has a later frost
Average last frost
May 25
about a 50% chance of a later one
Average first fall frost
Sep 16
1 year in 10 by Sep 5
Frost-free days
111
median, 1991–2020
Station used: Shelby · 0.9 km away · station 1014 m, town 1005 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 17 – May 1 | Jun 12 – Jun 26 | Aug 6 |
| Sweet pepper | Apr 3 – Apr 17 | Jun 12 – Jun 26 | Aug 11 |
| Lettuce (leaf) | Mar 23 – Mar 30 | Apr 27 – May 11 | Jun 6 |
| Peas | — | Apr 19 – May 17 | Jun 13 |
| Bush beans | — | Jun 5 – Jun 26 | Jul 25 |
| Carrot | — | May 4 – Jun 15 | Jul 3 |
| Beet | — | Apr 30 – Jun 11 | Jun 19 |
| Potato | — | May 4 – May 25 | Jul 13 |
| Kale | Mar 16 – Mar 30 | Apr 27 – May 11 | Jun 9 |
| Broccoli | Mar 16 – Mar 30 | Apr 27 – May 18 | Jun 26 |
| Cucumber | May 15 – May 22 | Jun 12 – Jun 26 | Aug 1 |
| Summer squash and zucchini | May 15 – May 22 | Jun 12 – Jun 26 | Jul 27 |
| Winter squash | May 15 – May 22 | Jun 12 – Jun 26 | Aug 31 |
| Sweet corn | — | Jun 5 – Jun 26 | Aug 4 |
| Onion (from sets) | — | Apr 27 – May 18 | Jul 26 |
| Garlic | — | Sep 2 – Sep 30 (fall) | following summer |
| Spinach | — | Apr 19 – May 17 | May 27 |
| Basil | May 1 – May 15 | Jun 12 – Jun 26 | Aug 8 |
Shelby'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 |
|---|---|
| 1951 | Jun 1 |
| 1952 | May 31 |
| 1953 | May 23 |
| 1954 | May 14 |
| 1955 | May 31 |
| 1956 | May 13 |
| 1957 | May 23 |
| 1995 | Jun 10 |
| 1997 | May 19 |
| 1998 | Jun 3 |
| 1999 | May 13 |
| 2000 | Jun 13 |
| 2001 | May 21 |
| 2002 | May 23 |
| 2003 | May 20 |
| 2004 | Jun 18 |
| 2005 | May 30 |
| 2006 | May 14 |
| 2007 | May 26 |
| 2008 | Jun 11 |
| 2009 | Jun 8 |
| 2010 | May 13 |
| 2011 | May 31 |
| 2012 | May 29 |
| 2013 | May 8 |
| 2014 | May 14 |
| 2015 | Jun 22 |
| 2016 | May 15 |
| 2017 | May 18 |
| 2018 | May 12 |
| 2019 | May 19 |
| 2020 | May 5 |
| 2021 | May 24 |
| 2022 | May 22 |
| 2023 | Apr 28 |
| 2024 | May 3 |
| 2025 | May 22 |
| 2026 | May 19 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1952 | 99 |
| 1953 | 120 |
| 1954 | 129 |
| 1955 | 101 |
| 1995 | 101 |
| 1997 | 122 |
| 1998 | 109 |
| 1999 | 121 |
| 2000 | 98 |
| 2001 | 133 |
| 2002 | 107 |
| 2003 | 119 |
| 2004 | 94 |
| 2005 | 116 |
| 2006 | 110 |
| 2007 | 109 |
| 2008 | 82 |
| 2009 | 111 |
| 2010 | 116 |
| 2011 | 111 |
| 2012 | 105 |
| 2013 | 134 |
| 2014 | 117 |
| 2015 | 76 |
| 2016 | 120 |
| 2017 | 121 |
| 2018 | 107 |
| 2019 | 130 |
| 2020 | 148 |
| 2021 | 130 |
| 2022 | 121 |
| 2023 | 160 |
| 2024 | 140 |
| 2025 | 136 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1952 | 14.4 °C |
| 1953 | 13.2 °C |
| 1954 | 13.2 °C |
| 1955 | 13.0 °C |
| 1957 | 14.4 °C |
| 1997 | 14.4 °C |
| 1998 | 16.1 °C |
| 1999 | 13.7 °C |
| 2009 | 13.8 °C |
| 2010 | 12.3 °C |
| 2011 | 13.2 °C |
| 2012 | 14.6 °C |
| 2013 | 14.1 °C |
| 2014 | 13.7 °C |
| 2015 | 14.6 °C |
| 2016 | 14.2 °C |
| 2017 | 15.1 °C |
| 2018 | 13.8 °C |
| 2019 | 13.6 °C |
| 2020 | 14.3 °C |
| 2021 | 15.0 °C |
| 2022 | 15.0 °C |
| 2023 | 16.0 °C |
| 2024 | 15.3 °C |
| 2025 | 15.1 °C |
| 2026 | 14.7 °C |
What this means for you: Since 1951, Shelby's last spring frost has come about 1 day earlier per decade, on average. The frost-free season has grown by about 2 days per decade. Year-to-year swings are large, so keep using the safe date rather than the trend.
Source: daily records from Shelby (NOAA GHCN-Daily). Years with too many missing days are left out.