Monson, MA frost dates
Last spring frostMay 7median date
First fall frostOct 12median date
Growing season158 daysfrost-free
Hardiness zone6aZone 6a
How Monson compares
- In 8 years out of 10, the last spring frost in Monson falls between April 23 and May 21, a 28-day window. The first fall frost falls between October 1 and October 27.
- The median last frost is 10 days later than the Massachusetts median of Apr 27.
- Its 158-day growing season is longer than 18% of the 510 Massachusetts places with a regular frost season (state median 169 days).
- The last frost is 8 days later than the zone 6a median of Apr 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6a chart.
- The weather station records an average of 152 nights a year at or below 32°F.
- Compared with Springfield, MA, 21 km away, the last frost here is 4 days later than there and the growing season is the same length.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 23 |
| 50% (median) | May 7 |
| 10% (safe for tender plants) | May 21 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 1 |
| 50% (median) | October 12 |
| 90% (late) | October 27 |
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 Monson, MA
Monson, MA frost dates — last frost May 7, first frost Oct 12, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Feb 12 to Feb 26Transplant outside: Apr 9 to Apr 23
Start indoors: Feb 26 to Mar 12Transplant outside: May 21 to Jun 4
Start indoors: Feb 26 to Mar 12Transplant outside: May 21 to Jun 4
Start indoors: Mar 12 to Mar 26Transplant outside: May 14 to May 28
Start indoors: Mar 12 to Mar 26Transplant outside: Apr 16 to Apr 30Sow outdoors: Apr 9 to May 14Plant for fall: Aug 17 to Sep 14
Start indoors: Mar 12 to Mar 26Transplant outside: Apr 9 to Apr 23Sow outdoors: Apr 9 to Apr 23Plant for fall: Aug 3 to Aug 24
Start indoors: Mar 12 to Mar 26Transplant outside: Apr 23 to May 7Plant for fall: Jul 6 to Jul 27
Start indoors: Mar 12 to Mar 26Transplant outside: Apr 16 to Apr 30Plant for fall: Jul 6 to Jul 27
Start indoors: Mar 12 to Mar 26Transplant outside: Apr 23 to May 7Plant for fall: Jul 6 to Jul 27
Start indoors: Mar 26 to Apr 9Transplant outside: May 28 to Jun 11Sow outdoors: May 28 to Jun 11
Start indoors: Mar 26 to Apr 9Transplant outside: May 14 to May 28
Sow outdoors: Mar 26 to Apr 16Plant for fall: Jul 20 to Aug 10
Sow outdoors: Mar 26 to Apr 16Plant for fall: Aug 17 to Sep 7
Sow outdoors: Apr 2 to May 14Plant for fall: Aug 31 to Sep 21
Start indoors: Apr 9 to Apr 16Transplant outside: May 21 to May 28Sow outdoors: May 14 to May 28Plant for fall: Jul 27 to Aug 10
Start indoors: Apr 9 to Apr 16Sow outdoors: May 14 to May 28Plant for fall: Aug 3 to Aug 17
Start indoors: Apr 9 to Apr 16Sow outdoors: May 14 to May 28
Start indoors: Apr 9 to Apr 16Transplant outside: May 21 to Jun 4
Sow outdoors: Apr 16 to May 14Plant for fall: Jul 20 to Aug 3
Sow outdoors: Apr 16 to May 14Plant for fall: Aug 3 to Aug 17
Sow outdoors: Apr 16 to May 7
Sow outdoors: Apr 23 to May 21Plant for fall: Aug 3 to Aug 17
Sow outdoors: Apr 23 to May 14Plant for fall: Aug 17 to Sep 7
Sow outdoors: May 14 to Jun 4Plant for fall: Jul 27 to Aug 10
Sow outdoors: May 14 to May 28
Transplant outside: May 21 to Jun 11
Plant for fall: Sep 28 to Nov 2
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Monson, MA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 12 – Feb 26 | Apr 9 – Apr 23 | — | — |
| Peppers | Feb 26 – Mar 12 | May 21 – Jun 4 | — | — |
| Eggplant | Feb 26 – Mar 12 | May 21 – Jun 4 | — | — |
| Tomatoes | Mar 12 – Mar 26 | May 14 – May 28 | — | — |
| Lettuce | Mar 12 – Mar 26 | Apr 16 – Apr 30 | Apr 9 – May 14 | Aug 17 – Sep 14 |
| Kale | Mar 12 – Mar 26 | Apr 9 – Apr 23 | Apr 9 – Apr 23 | Aug 3 – Aug 24 |
| Broccoli | Mar 12 – Mar 26 | Apr 23 – May 7 | — | Jul 6 – Jul 27 |
| Cabbage | Mar 12 – Mar 26 | Apr 16 – Apr 30 | — | Jul 6 – Jul 27 |
| Cauliflower | Mar 12 – Mar 26 | Apr 23 – May 7 | — | Jul 6 – Jul 27 |
| Okra | Mar 26 – Apr 9 | May 28 – Jun 11 | May 28 – Jun 11 | — |
| Basil | Mar 26 – Apr 9 | May 14 – May 28 | — | — |
| Peas | — | — | Mar 26 – Apr 16 | Jul 20 – Aug 10 |
| Spinach | — | — | Mar 26 – Apr 16 | Aug 17 – Sep 7 |
| Radishes | — | — | Apr 2 – May 14 | Aug 31 – Sep 21 |
| Cucumbers | Apr 9 – Apr 16 | May 21 – May 28 | May 14 – May 28 | Jul 27 – Aug 10 |
| Zucchini & Summer Squash | Apr 9 – Apr 16 | — | May 14 – May 28 | Aug 3 – Aug 17 |
| Winter Squash & Pumpkins | Apr 9 – Apr 16 | — | May 14 – May 28 | — |
| Melons & Watermelon | Apr 9 – Apr 16 | May 21 – Jun 4 | — | — |
| Carrots | — | — | Apr 16 – May 14 | Jul 20 – Aug 3 |
| Beets | — | — | Apr 16 – May 14 | Aug 3 – Aug 17 |
| Potatoes | — | — | Apr 16 – May 7 | — |
| Swiss Chard | — | — | Apr 23 – May 21 | Aug 3 – Aug 17 |
| Cilantro | — | — | Apr 23 – May 14 | Aug 17 – Sep 7 |
| Green Beans | — | — | May 14 – Jun 4 | Jul 27 – Aug 10 |
| Sweet Corn | — | — | May 14 – May 28 | — |
| Sweet Potatoes | — | May 21 – Jun 11 | — | — |
| Garlic | — | — | — | Sep 28 – Nov 2 |
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 Staffordville, CT weather station, 12 km away (elevation 735 ft (224 m)).
Frost dates near Monson
- Palmer May 3 · Oct 14
- Three Rivers May 3 · Oct 14
- Hampden May 7 · Oct 12
- Thorndike May 3 · Oct 14
- Wales Apr 28 · Oct 15
- Wilbraham May 3 · Oct 14
- Brimfield Apr 28 · Oct 15
- Bondsville May 3 · Oct 14
- West Warren May 3 · Oct 14
- Ludlow May 3 · Oct 14
Frequently asked questions
When is the last frost in Monson, MA?
The median last spring frost in Monson, MA is May 7. There is still about a 10% chance of frost after May 21, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Monson, MA?
The median first fall frost is October 12, with about a 10% chance of frost before October 1.
How long is the growing season in Monson, MA?
About 158 days between the median last spring frost and first fall frost.
What planting zone is Monson, MA?
Monson, MA is in USDA hardiness zone 6a.