Johnston, RI frost dates
Last spring frostApr 11median date
First fall frostOct 30median date
Growing season202 daysfrost-free
Hardiness zone6bZone 6b
How Johnston compares
- In 8 years out of 10, the last spring frost in Johnston falls between April 1 and April 23, a 22-day window. The first fall frost falls between October 16 and November 12.
- The median last frost is 11 days earlier than the Rhode Island median of Apr 22.
- Its 202-day growing season is longer than 61% of the 70 Rhode Island places with a regular frost season (state median 181 days).
- The last frost is 11 days earlier than the zone 6b median of Apr 22. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6b chart.
- The weather station records an average of 109 nights a year at or below 32°F.
- Johnston shares its weather station with Cranston, RI, 8 km away, so the two have the same frost dates.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 1 |
| 50% (median) | April 11 |
| 10% (safe for tender plants) | April 23 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 16 |
| 50% (median) | October 30 |
| 90% (late) | November 12 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Johnston, RI
Johnston, RI frost dates — last frost Apr 11, first frost Oct 30, zone 6b. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Jan 17 to Jan 31Transplant outside: Mar 14 to Mar 28
Start indoors: Jan 31 to Feb 14Transplant outside: Apr 25 to May 9
Start indoors: Jan 31 to Feb 14Transplant outside: Apr 25 to May 9
Start indoors: Feb 14 to Feb 28Transplant outside: Apr 18 to May 2
Start indoors: Feb 14 to Feb 28Transplant outside: Mar 21 to Apr 4Sow outdoors: Mar 14 to Apr 18Plant for fall: Sep 4 to Oct 2
Start indoors: Feb 14 to Feb 28Transplant outside: Mar 14 to Mar 28Sow outdoors: Mar 14 to Mar 28Plant for fall: Aug 21 to Sep 11
Start indoors: Feb 14 to Feb 28Transplant outside: Mar 28 to Apr 11Plant for fall: Jul 24 to Aug 14
Start indoors: Feb 14 to Feb 28Transplant outside: Mar 21 to Apr 4Plant for fall: Jul 24 to Aug 14
Start indoors: Feb 14 to Feb 28Transplant outside: Mar 28 to Apr 11Plant for fall: Jul 24 to Aug 14
Start indoors: Feb 28 to Mar 14Transplant outside: May 2 to May 16Sow outdoors: May 2 to May 16
Start indoors: Feb 28 to Mar 14Transplant outside: Apr 18 to May 2
Sow outdoors: Feb 28 to Mar 21Plant for fall: Aug 7 to Aug 28
Sow outdoors: Feb 28 to Mar 21Plant for fall: Sep 4 to Sep 25
Sow outdoors: Mar 7 to Apr 18Plant for fall: Sep 18 to Oct 9
Start indoors: Mar 14 to Mar 21Transplant outside: Apr 25 to May 2Sow outdoors: Apr 18 to May 2Plant for fall: Aug 14 to Aug 28
Start indoors: Mar 14 to Mar 21Sow outdoors: Apr 18 to May 2Plant for fall: Aug 21 to Sep 4
Start indoors: Mar 14 to Mar 21Sow outdoors: Apr 18 to May 2
Start indoors: Mar 14 to Mar 21Transplant outside: Apr 25 to May 9
Sow outdoors: Mar 21 to Apr 18Plant for fall: Aug 7 to Aug 21
Sow outdoors: Mar 21 to Apr 18Plant for fall: Aug 21 to Sep 4
Sow outdoors: Mar 21 to Apr 11
Sow outdoors: Mar 28 to Apr 25Plant for fall: Aug 21 to Sep 4
Sow outdoors: Mar 28 to Apr 18Plant for fall: Sep 4 to Sep 25
Sow outdoors: Apr 18 to May 9Plant for fall: Aug 14 to Aug 28
Sow outdoors: Apr 18 to May 2
Transplant outside: Apr 25 to May 16
Plant for fall: Oct 16 to Nov 20
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Johnston, RI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 17 – Jan 31 | Mar 14 – Mar 28 | — | — |
| Peppers | Jan 31 – Feb 14 | Apr 25 – May 9 | — | — |
| Eggplant | Jan 31 – Feb 14 | Apr 25 – May 9 | — | — |
| Tomatoes | Feb 14 – Feb 28 | Apr 18 – May 2 | — | — |
| Lettuce | Feb 14 – Feb 28 | Mar 21 – Apr 4 | Mar 14 – Apr 18 | Sep 4 – Oct 2 |
| Kale | Feb 14 – Feb 28 | Mar 14 – Mar 28 | Mar 14 – Mar 28 | Aug 21 – Sep 11 |
| Broccoli | Feb 14 – Feb 28 | Mar 28 – Apr 11 | — | Jul 24 – Aug 14 |
| Cabbage | Feb 14 – Feb 28 | Mar 21 – Apr 4 | — | Jul 24 – Aug 14 |
| Cauliflower | Feb 14 – Feb 28 | Mar 28 – Apr 11 | — | Jul 24 – Aug 14 |
| Okra | Feb 28 – Mar 14 | May 2 – May 16 | May 2 – May 16 | — |
| Basil | Feb 28 – Mar 14 | Apr 18 – May 2 | — | — |
| Peas | — | — | Feb 28 – Mar 21 | Aug 7 – Aug 28 |
| Spinach | — | — | Feb 28 – Mar 21 | Sep 4 – Sep 25 |
| Radishes | — | — | Mar 7 – Apr 18 | Sep 18 – Oct 9 |
| Cucumbers | Mar 14 – Mar 21 | Apr 25 – May 2 | Apr 18 – May 2 | Aug 14 – Aug 28 |
| Zucchini & Summer Squash | Mar 14 – Mar 21 | — | Apr 18 – May 2 | Aug 21 – Sep 4 |
| Winter Squash & Pumpkins | Mar 14 – Mar 21 | — | Apr 18 – May 2 | — |
| Melons & Watermelon | Mar 14 – Mar 21 | Apr 25 – May 9 | — | — |
| Carrots | — | — | Mar 21 – Apr 18 | Aug 7 – Aug 21 |
| Beets | — | — | Mar 21 – Apr 18 | Aug 21 – Sep 4 |
| Potatoes | — | — | Mar 21 – Apr 11 | — |
| Swiss Chard | — | — | Mar 28 – Apr 25 | Aug 21 – Sep 4 |
| Cilantro | — | — | Mar 28 – Apr 18 | Sep 4 – Sep 25 |
| Green Beans | — | — | Apr 18 – May 9 | Aug 14 – Aug 28 |
| Sweet Corn | — | — | Apr 18 – May 2 | — |
| Sweet Potatoes | — | Apr 25 – May 16 | — | — |
| Garlic | — | — | — | Oct 16 – Nov 20 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Providence T F Green Ap, RI weather station, 14 km away (elevation 59 ft (18 m)).
Frost dates near Johnston
- North Providence Apr 22 · Oct 19
- Greenville Apr 22 · Oct 19
- Cranston Apr 11 · Oct 30
- Smithfield Apr 22 · Oct 19
- Harmony Apr 25 · Oct 19
- Providence Apr 11 · Oct 30
- North Scituate Apr 25 · Oct 19
- Hope Apr 22 · Oct 20
- Fiskeville Apr 22 · Oct 20
- Lincoln Apr 22 · Oct 19
Frequently asked questions
When is the last frost in Johnston, RI?
The median last spring frost in Johnston, RI is April 11. There is still about a 10% chance of frost after April 23, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Johnston, RI?
The median first fall frost is October 30, with about a 10% chance of frost before October 16.
How long is the growing season in Johnston, RI?
About 202 days between the median last spring frost and first fall frost.
What planting zone is Johnston, RI?
Johnston, RI is in USDA hardiness zone 6b.