When to plant in Lewiston, UT
Planting dates worked out from Lewiston's own frost records, not a generic zone chart.
Safe to plant out
Jun 9
1 year in 10 has a later frost
Average last frost
May 21
about a 50% chance of a later one
Average first fall frost
Sep 19
1 year in 10 by Aug 26
Frost-free days
124
median, 1991–2020
Station used: Trenton · 8.1 km away · station 1358 m, town 1374 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 14 – Apr 28 | Jun 9 – Jun 23 | Aug 3 |
| Sweet pepper | Mar 31 – Apr 14 | Jun 9 – Jun 23 | Aug 8 |
| Lettuce (leaf) | Mar 19 – Mar 26 | Apr 23 – May 7 | Jun 2 |
| Peas | — | Apr 9 – May 7 | Jun 3 |
| Bush beans | — | Jun 2 – Jun 23 | Jul 22 |
| Carrot | — | Apr 30 – Jun 11 | Jun 29 |
| Beet | — | Apr 23 – Jun 4 | Jun 12 |
| Potato | — | Apr 30 – May 21 | Jul 9 |
| Kale | Mar 12 – Mar 26 | Apr 23 – May 7 | Jun 5 |
| Broccoli | Mar 12 – Mar 26 | Apr 23 – May 14 | Jun 22 |
| Cucumber | May 12 – May 19 | Jun 9 – Jun 23 | Jul 29 |
| Summer squash and zucchini | May 12 – May 19 | Jun 9 – Jun 23 | Jul 24 |
| Winter squash Season likely too short |
May 12 – May 19 | Jun 9 – Jun 23 | Aug 28 |
| Sweet corn | — | Jun 2 – Jun 23 | Aug 1 |
| Onion (from sets) | — | Apr 23 – May 14 | Jul 22 |
| Garlic | — | Sep 5 – Oct 3 (fall) | following summer |
| Spinach | — | Apr 9 – May 7 | May 17 |
| Basil | Apr 28 – May 12 | Jun 9 – Jun 23 | Aug 5 |
Lewiston'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 |
|---|---|
| 1945 | Jun 16 |
| 1946 | May 31 |
| 1947 | Jun 30 |
| 1977 | May 30 |
| 1978 | Jun 11 |
| 1979 | Jun 9 |
| 1980 | May 14 |
| 1981 | Jun 14 |
| 1982 | Jun 9 |
| 1983 | May 15 |
| 1984 | Jun 2 |
| 1985 | May 14 |
| 1986 | May 23 |
| 1987 | May 4 |
| 1988 | May 20 |
| 1989 | Jun 21 |
| 1991 | May 19 |
| 1993 | Jun 13 |
| 1998 | Apr 28 |
| 1999 | May 17 |
| 2000 | Jun 1 |
| 2001 | Jun 5 |
| 2002 | Jun 10 |
| 2003 | May 20 |
| 2010 | May 5 |
| 2011 | May 31 |
| 2012 | Jun 6 |
| 2013 | May 3 |
| 2014 | May 14 |
| 2016 | May 12 |
| 2017 | May 19 |
| 2018 | May 3 |
| 2019 | May 10 |
| 2020 | Jun 9 |
| 2021 | Jun 11 |
| 2022 | Jun 15 |
| 2023 | Apr 28 |
| 2024 | Jun 18 |
| 2025 | May 19 |
| 2026 | May 22 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1945 | 94 |
| 1977 | 101 |
| 1978 | 98 |
| 1979 | 93 |
| 1980 | 104 |
| 1981 | 103 |
| 1982 | 114 |
| 1983 | 127 |
| 1984 | 111 |
| 1985 | 121 |
| 1986 | 110 |
| 1987 | 135 |
| 1988 | 121 |
| 1989 | 74 |
| 1998 | 159 |
| 1999 | 132 |
| 2000 | 113 |
| 2001 | 94 |
| 2002 | 121 |
| 2010 | 175 |
| 2011 | 130 |
| 2012 | 56 |
| 2013 | 139 |
| 2014 | 120 |
| 2016 | 120 |
| 2017 | 126 |
| 2018 | 140 |
| 2019 | 108 |
| 2021 | 101 |
| 2022 | 118 |
| 2023 | 169 |
| 2024 | 122 |
| 2025 | 140 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1945 | 14.6 °C |
| 1946 | 16.9 °C |
| 1947 | 15.5 °C |
| 1977 | 15.3 °C |
| 1978 | 14.1 °C |
| 1979 | 15.0 °C |
| 1980 | 14.7 °C |
| 1981 | 15.4 °C |
| 1982 | 14.4 °C |
| 1983 | 14.3 °C |
| 1984 | 14.7 °C |
| 1985 | 15.4 °C |
| 1986 | 15.0 °C |
| 1987 | 16.2 °C |
| 1988 | 16.3 °C |
| 1989 | 15.9 °C |
| 1992 | 15.9 °C |
| 1993 | 13.0 °C |
| 1998 | 15.8 °C |
| 1999 | 15.0 °C |
| 2000 | 16.4 °C |
| 2001 | 16.6 °C |
| 2002 | 16.1 °C |
| 2010 | 16.1 °C |
| 2011 | 15.8 °C |
| 2012 | 15.4 °C |
| 2013 | 16.6 °C |
| 2014 | 16.0 °C |
| 2016 | 16.0 °C |
| 2017 | 15.9 °C |
| 2018 | 16.4 °C |
| 2019 | 15.3 °C |
| 2021 | 16.2 °C |
| 2022 | 15.8 °C |
| 2023 | 15.8 °C |
| 2024 | 16.3 °C |
| 2025 | 16.7 °C |
What this means for you: Since 1945, Lewiston's last spring frost has come about 3 days earlier per decade, on average. The frost-free season has grown by about 5 days per decade. Year-to-year swings are large, so keep using the safe date rather than the trend.
Source: daily records from Trenton (NOAA GHCN-Daily). Years with too many missing days are left out.