When to plant in Cool, CA
Planting dates worked out from Cool's own frost records, not a generic zone chart.
Safe to plant out
Apr 18
1 year in 10 has a later frost
Average last frost
Mar 26
about a 50% chance of a later one
Average first fall frost
Nov 24
1 year in 10 by Nov 7
Frost-free days
231
median, 1991–2020
Station used: Pilot Hill California · 6.1 km away · station 366 m, town 467 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 | Feb 21 – Mar 7 | Apr 18 – May 2 | Jun 12 |
| Sweet pepper | Feb 7 – Feb 21 | Apr 18 – May 2 | Jun 17 |
| Lettuce (leaf) | Jan 22 – Jan 29 | Feb 26 – Mar 12 | Apr 7 |
| Peas | — | Feb 12 – Mar 12 | Apr 8 |
| Bush beans | — | Apr 11 – May 2 | May 31 |
| Carrot | — | Mar 5 – Apr 16 | May 4 |
| Beet | — | Feb 26 – Apr 9 | Apr 17 |
| Potato | — | Mar 5 – Mar 26 | May 14 |
| Kale | Jan 15 – Jan 29 | Feb 26 – Mar 12 | Apr 10 |
| Broccoli | Jan 15 – Jan 29 | Feb 26 – Mar 19 | Apr 27 |
| Cucumber | Mar 21 – Mar 28 | Apr 18 – May 2 | Jun 7 |
| Summer squash and zucchini | Mar 21 – Mar 28 | Apr 18 – May 2 | Jun 2 |
| Winter squash | Mar 21 – Mar 28 | Apr 18 – May 2 | Jul 7 |
| Sweet corn | — | Apr 11 – May 2 | Jun 10 |
| Onion (from sets) | — | Feb 26 – Mar 19 | May 27 |
| Garlic | — | Nov 9 – Dec 7 (fall) | following summer |
| Spinach | — | Feb 12 – Mar 12 | Mar 22 |
| Basil | Mar 7 – Mar 21 | Apr 18 – May 2 | Jun 14 |
Cool'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 |
|---|---|
| 1994 | Mar 23 |
| 1995 | Apr 14 |
| 1996 | Mar 29 |
| 1997 | Mar 4 |
| 1998 | Apr 15 |
| 1999 | Apr 10 |
| 2000 | May 11 |
| 2001 | Apr 12 |
| 2002 | Apr 16 |
| 2003 | Apr 15 |
| 2004 | Mar 1 |
| 2005 | Apr 14 |
| 2006 | Mar 22 |
| 2007 | Apr 19 |
| 2008 | Apr 21 |
| 2009 | Apr 15 |
| 2010 | Mar 14 |
| 2011 | Apr 10 |
| 2012 | Apr 6 |
| 2013 | Feb 22 |
| 2014 | Feb 5 |
| 2015 | Jan 4 |
| 2016 | Feb 3 |
| 2017 | Apr 9 |
| 2018 | Apr 17 |
| 2019 | Feb 23 |
| 2020 | Apr 2 |
| 2021 | Mar 16 |
| 2022 | May 11 |
| 2023 | Apr 19 |
| 2024 | Apr 14 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1994 | 232 |
| 1995 | 246 |
| 1996 | 245 |
| 1997 | 279 |
| 1998 | 207 |
| 1999 | 225 |
| 2000 | 181 |
| 2001 | 227 |
| 2002 | 245 |
| 2003 | 199 |
| 2004 | 266 |
| 2005 | 225 |
| 2006 | 222 |
| 2007 | 218 |
| 2008 | 227 |
| 2009 | 231 |
| 2010 | 253 |
| 2011 | 208 |
| 2012 | 217 |
| 2013 | 284 |
| 2014 | 323 |
| 2015 | 324 |
| 2016 | 286 |
| 2017 | 240 |
| 2018 | 228 |
| 2019 | 275 |
| 2020 | 219 |
| 2021 | 268 |
| 2022 | 182 |
| 2023 | 221 |
| 2024 | 215 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1993 | 19.9 °C |
| 1994 | 20.0 °C |
| 1995 | 18.9 °C |
| 1996 | 20.6 °C |
| 1997 | 20.7 °C |
| 1999 | 19.0 °C |
| 2000 | 19.9 °C |
| 2001 | 20.4 °C |
| 2002 | 20.0 °C |
| 2003 | 19.9 °C |
| 2004 | 20.3 °C |
| 2005 | 19.6 °C |
| 2006 | 20.7 °C |
| 2007 | 20.0 °C |
| 2008 | 20.9 °C |
| 2009 | 20.7 °C |
| 2010 | 19.0 °C |
| 2011 | 19.3 °C |
| 2012 | 20.7 °C |
| 2013 | 21.0 °C |
| 2014 | 21.2 °C |
| 2015 | 20.7 °C |
| 2016 | 20.9 °C |
| 2017 | 21.4 °C |
| 2018 | 20.7 °C |
| 2019 | 20.6 °C |
| 2020 | 21.7 °C |
| 2021 | 22.1 °C |
| 2022 | 21.3 °C |
| 2023 | 20.2 °C |
| 2024 | 20.7 °C |
What this means for you: Since 1994, Cool's last spring frost has come about 5 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 Pilot Hill California (NOAA GHCN-Daily). Years with too many missing days are left out.