When to plant in Thermal, CA
Planting dates worked out from Thermal's own frost records, not a generic zone chart.
Safe to plant out
Mar 3
1 year in 10 has a later frost
Average last frost
Feb 8
about a 50% chance of a later one
Average first fall frost
Dec 1
1 year in 10 by Nov 10
Frost-free days
290
median, 1991–2020
Station used: Desert Resorts Rgnl Ap · 2.5 km away · station -36 m, town -36 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 | Jan 6 – Jan 20 | Mar 3 – Mar 17 | Apr 27 |
| Sweet pepper | Dec 23 – Jan 6 | Mar 3 – Mar 17 | May 2 |
| Lettuce (leaf) | Dec 7 – Dec 14 | Jan 11 – Jan 25 | Feb 20 |
| Peas | — | Dec 28 – Jan 25 | Feb 21 |
| Bush beans | — | Feb 24 – Mar 17 | Apr 15 |
| Carrot | — | Jan 18 – Mar 1 | Mar 19 |
| Beet | — | Jan 11 – Feb 22 | Mar 2 |
| Potato | — | Jan 18 – Feb 8 | Mar 29 |
| Kale | Nov 30 – Dec 14 | Jan 11 – Jan 25 | Feb 23 |
| Broccoli | Nov 30 – Dec 14 | Jan 11 – Feb 1 | Mar 12 |
| Cucumber | Feb 3 – Feb 10 | Mar 3 – Mar 17 | Apr 22 |
| Summer squash and zucchini | Feb 3 – Feb 10 | Mar 3 – Mar 17 | Apr 17 |
| Winter squash | Feb 3 – Feb 10 | Mar 3 – Mar 17 | May 22 |
| Sweet corn | — | Feb 24 – Mar 17 | Apr 25 |
| Onion (from sets) | — | Jan 11 – Feb 1 | Apr 11 |
| Garlic | — | Nov 17 – Dec 15 (fall) | following summer |
| Spinach | — | Dec 28 – Jan 25 | Feb 4 |
| Basil | Jan 20 – Feb 3 | Mar 3 – Mar 17 | Apr 29 |
Thermal'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 | Mar 4 |
| 1952 | Feb 15 |
| 1953 | Feb 23 |
| 1954 | Jan 16 |
| 1955 | Feb 22 |
| 1956 | Mar 13 |
| 1958 | Jan 24 |
| 1959 | Jan 21 |
| 1960 | Feb 25 |
| 1961 | Jan 8 |
| 1962 | Mar 15 |
| 1963 | Jan 23 |
| 1964 | Mar 1 |
| 1965 | Mar 5 |
| 1966 | Mar 4 |
| 1967 | Feb 22 |
| 1968 | Jan 30 |
| 1969 | Feb 20 |
| 1970 | Jan 30 |
| 1971 | Mar 6 |
| 1972 | Feb 12 |
| 1973 | Jan 30 |
| 1974 | Jan 3 |
| 1975 | Feb 23 |
| 1976 | Jan 14 |
| 1977 | Mar 3 |
| 1978 | Jan 25 |
| 1979 | Feb 2 |
| 1980 | Feb 12 |
| 1981 | Feb 2 |
| 1982 | Feb 3 |
| 1983 | Jan 4 |
| 1984 | Mar 6 |
| 1985 | Mar 3 |
| 1986 | Feb 10 |
| 1987 | Jan 22 |
| 1988 | Jan 21 |
| 1989 | Feb 13 |
| 1990 | Feb 19 |
| 1991 | Jan 31 |
| 1992 | Jan 24 |
| 1993 | Jan 5 |
| 1994 | Feb 24 |
| 1995 | Jan 2 |
| 1996 | Feb 27 |
| 1997 | Mar 6 |
| 1998 | Jan 23 |
| 1999 | Apr 10 |
| 2000 | Jan 13 |
| 2001 | Feb 24 |
| 2002 | Mar 9 |
| 2003 | Feb 10 |
| 2004 | Feb 15 |
| 2006 | Jan 22 |
| 2007 | Mar 2 |
| 2008 | Feb 6 |
| 2009 | Feb 12 |
| 2010 | Jan 5 |
| 2011 | Feb 28 |
| 2012 | Mar 3 |
| 2013 | Feb 26 |
| 2014 | Feb 2 |
| 2015 | Jan 23 |
| 2016 | Feb 4 |
| 2018 | Feb 26 |
| 2019 | Feb 12 |
| 2020 | Feb 13 |
| 2021 | Mar 2 |
| 2022 | Mar 12 |
| 2023 | Mar 4 |
| 2024 | Jan 13 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1951 | 285 |
| 1952 | 282 |
| 1953 | 268 |
| 1954 | 339 |
| 1955 | 311 |
| 1956 | 235 |
| 1957 | 332 |
| 1958 | 296 |
| 1959 | 343 |
| 1960 | 286 |
| 1961 | 333 |
| 1962 | 287 |
| 1963 | 323 |
| 1964 | 286 |
| 1965 | 300 |
| 1966 | 293 |
| 1967 | 283 |
| 1968 | 308 |
| 1969 | 296 |
| 1970 | 334 |
| 1971 | 237 |
| 1972 | 296 |
| 1973 | 307 |
| 1974 | 330 |
| 1975 | 269 |
| 1976 | 317 |
| 1977 | 302 |
| 1978 | 313 |
| 1979 | 292 |
| 1980 | 275 |
| 1981 | 323 |
| 1982 | 320 |
| 1983 | 335 |
| 1984 | 283 |
| 1985 | 261 |
| 1986 | 303 |
| 1987 | 326 |
| 1988 | 339 |
| 1990 | 281 |
| 1991 | 299 |
| 1992 | 291 |
| 1993 | 318 |
| 1994 | 251 |
| 1995 | 353 |
| 1996 | 276 |
| 1997 | 273 |
| 1998 | 290 |
| 1999 | 226 |
| 2000 | 299 |
| 2001 | 283 |
| 2002 | 284 |
| 2003 | 285 |
| 2004 | 287 |
| 2005 | 330 |
| 2006 | 310 |
| 2007 | 286 |
| 2008 | 323 |
| 2009 | 294 |
| 2010 | 323 |
| 2011 | 277 |
| 2012 | 290 |
| 2013 | 281 |
| 2014 | 327 |
| 2015 | 308 |
| 2016 | 293 |
| 2017 | 351 |
| 2018 | 281 |
| 2019 | 260 |
| 2020 | 293 |
| 2021 | 283 |
| 2022 | 253 |
| 2023 | 280 |
| 2024 | 312 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1951 | 29.0 °C |
| 1952 | 29.6 °C |
| 1953 | 28.4 °C |
| 1954 | 29.0 °C |
| 1955 | 28.0 °C |
| 1956 | 29.0 °C |
| 1957 | 29.4 °C |
| 1958 | 29.9 °C |
| 1959 | 29.4 °C |
| 1960 | 29.9 °C |
| 1961 | 29.2 °C |
| 1962 | 29.0 °C |
| 1963 | 28.3 °C |
| 1964 | 28.2 °C |
| 1965 | 27.6 °C |
| 1966 | 29.4 °C |
| 1967 | 27.9 °C |
| 1968 | 28.5 °C |
| 1969 | 29.5 °C |
| 1970 | 28.9 °C |
| 1971 | 28.0 °C |
| 1972 | 28.4 °C |
| 1973 | 28.7 °C |
| 1974 | 28.8 °C |
| 1975 | 27.3 °C |
| 1976 | 27.6 °C |
| 1977 | 28.1 °C |
| 1978 | 28.4 °C |
| 1979 | 28.3 °C |
| 1980 | 28.2 °C |
| 1981 | 29.5 °C |
| 1982 | 28.3 °C |
| 1983 | 28.3 °C |
| 1984 | 29.6 °C |
| 1985 | 29.0 °C |
| 1986 | 28.8 °C |
| 1987 | 28.8 °C |
| 1988 | 28.5 °C |
| 1990 | 29.3 °C |
| 1991 | 27.8 °C |
| 1992 | 28.4 °C |
| 1993 | 28.0 °C |
| 1994 | 28.4 °C |
| 1995 | 28.2 °C |
| 1996 | 29.3 °C |
| 1997 | 29.1 °C |
| 1998 | 28.0 °C |
| 1999 | 27.5 °C |
| 2000 | 29.3 °C |
| 2001 | 29.0 °C |
| 2002 | 28.2 °C |
| 2003 | 28.9 °C |
| 2004 | 28.4 °C |
| 2005 | 28.6 °C |
| 2006 | 29.1 °C |
| 2007 | 28.7 °C |
| 2008 | 29.5 °C |
| 2009 | 29.3 °C |
| 2010 | 27.9 °C |
| 2011 | 28.4 °C |
| 2012 | 29.7 °C |
| 2013 | 29.5 °C |
| 2014 | 29.7 °C |
| 2015 | 29.0 °C |
| 2016 | 29.4 °C |
| 2017 | 29.9 °C |
| 2018 | 31.3 °C |
| 2019 | 30.3 °C |
| 2020 | 30.5 °C |
| 2021 | 30.4 °C |
| 2022 | 29.9 °C |
| 2023 | 29.2 °C |
| 2024 | 30.2 °C |
What this means for you: Since 1951, Thermal's last spring frost has stayed at about the same time of year. The frost-free season has shrunk by about 1 days per decade. Year-to-year swings are large, so keep using the safe date rather than the trend.
Source: daily records from Desert Resorts Rgnl Ap (NOAA GHCN-Daily). Years with too many missing days are left out.