Winifred, MT frost dates
Last spring frostMay 16median date
First fall frostSep 23median date
Growing season130 daysfrost-free
Hardiness zone4bZone 4b
How Winifred compares
- In 8 years out of 10, the last spring frost in Winifred falls between May 5 and May 30, a 25-day window. The first fall frost falls between September 9 and October 2.
- The median last frost is 3 days earlier than the Montana median of May 19.
- Its 130-day growing season is longer than 60% of the 325 Montana places with a regular frost season (state median 125 days).
- The last frost is 8 days later than the zone 4b median of May 8. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 4b chart.
- The weather station records an average of 184 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 5 |
| 50% (median) | May 16 |
| 10% (safe for tender plants) | May 30 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 9 |
| 50% (median) | September 23 |
| 90% (late) | October 2 |
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 Winifred, MT
Winifred, MT frost dates — last frost May 16, first frost Sep 23, zone 4b. whenisthelastfrost.com
Crop
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Start indoors: Feb 21 to Mar 7Transplant outside: Apr 18 to May 2
Start indoors: Mar 7 to Mar 21Transplant outside: May 30 to Jun 13
Start indoors: Mar 7 to Mar 21Transplant outside: May 30 to Jun 13
Start indoors: Mar 21 to Apr 4Transplant outside: May 23 to Jun 6
Start indoors: Mar 21 to Apr 4Transplant outside: Apr 25 to May 9Sow outdoors: Apr 18 to May 23Plant for fall: Jul 29 to Aug 26
Start indoors: Mar 21 to Apr 4Transplant outside: Apr 18 to May 2Sow outdoors: Apr 18 to May 2Plant for fall: Jul 15 to Aug 5
Start indoors: Mar 21 to Apr 4Transplant outside: May 2 to May 16Plant for fall: Jun 17 to Jul 8
Start indoors: Mar 21 to Apr 4Transplant outside: Apr 25 to May 9Plant for fall: Jun 17 to Jul 8
Start indoors: Mar 21 to Apr 4Transplant outside: May 2 to May 16Plant for fall: Jun 17 to Jul 8
Start indoors: Apr 4 to Apr 18Transplant outside: Jun 6 to Jun 20Sow outdoors: Jun 6 to Jun 20
Start indoors: Apr 4 to Apr 18Transplant outside: May 23 to Jun 6
Sow outdoors: Apr 4 to Apr 25Plant for fall: Jul 1 to Jul 22
Sow outdoors: Apr 4 to Apr 25Plant for fall: Jul 29 to Aug 19
Sow outdoors: Apr 11 to May 23Plant for fall: Aug 12 to Sep 2
Start indoors: Apr 18 to Apr 25Transplant outside: May 30 to Jun 6Sow outdoors: May 23 to Jun 6Plant for fall: Jul 8 to Jul 22
Start indoors: Apr 18 to Apr 25Sow outdoors: May 23 to Jun 6Plant for fall: Jul 15 to Jul 29
Start indoors: Apr 18 to Apr 25Sow outdoors: May 23 to Jun 6
Start indoors: Apr 18 to Apr 25Transplant outside: May 30 to Jun 13
Sow outdoors: Apr 25 to May 23Plant for fall: Jul 1 to Jul 15
Sow outdoors: Apr 25 to May 23Plant for fall: Jul 15 to Jul 29
Sow outdoors: Apr 25 to May 16
Sow outdoors: May 2 to May 30Plant for fall: Jul 15 to Jul 29
Sow outdoors: May 2 to May 23Plant for fall: Jul 29 to Aug 19
Sow outdoors: May 23 to Jun 13Plant for fall: Jul 8 to Jul 22
Sow outdoors: May 23 to Jun 6
Transplant outside: May 30 to Jun 20
Plant for fall: Sep 9 to Oct 14
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Winifred, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 21 – Mar 7 | Apr 18 – May 2 | — | — |
| Peppers | Mar 7 – Mar 21 | May 30 – Jun 13 | — | — |
| Eggplant | Mar 7 – Mar 21 | May 30 – Jun 13 | — | — |
| Tomatoes | Mar 21 – Apr 4 | May 23 – Jun 6 | — | — |
| Lettuce | Mar 21 – Apr 4 | Apr 25 – May 9 | Apr 18 – May 23 | Jul 29 – Aug 26 |
| Kale | Mar 21 – Apr 4 | Apr 18 – May 2 | Apr 18 – May 2 | Jul 15 – Aug 5 |
| Broccoli | Mar 21 – Apr 4 | May 2 – May 16 | — | Jun 17 – Jul 8 |
| Cabbage | Mar 21 – Apr 4 | Apr 25 – May 9 | — | Jun 17 – Jul 8 |
| Cauliflower | Mar 21 – Apr 4 | May 2 – May 16 | — | Jun 17 – Jul 8 |
| Okra | Apr 4 – Apr 18 | Jun 6 – Jun 20 | Jun 6 – Jun 20 | — |
| Basil | Apr 4 – Apr 18 | May 23 – Jun 6 | — | — |
| Peas | — | — | Apr 4 – Apr 25 | Jul 1 – Jul 22 |
| Spinach | — | — | Apr 4 – Apr 25 | Jul 29 – Aug 19 |
| Radishes | — | — | Apr 11 – May 23 | Aug 12 – Sep 2 |
| Cucumbers | Apr 18 – Apr 25 | May 30 – Jun 6 | May 23 – Jun 6 | Jul 8 – Jul 22 |
| Zucchini & Summer Squash | Apr 18 – Apr 25 | — | May 23 – Jun 6 | Jul 15 – Jul 29 |
| Winter Squash & Pumpkins | Apr 18 – Apr 25 | — | May 23 – Jun 6 | — |
| Melons & Watermelon | Apr 18 – Apr 25 | May 30 – Jun 13 | — | — |
| Carrots | — | — | Apr 25 – May 23 | Jul 1 – Jul 15 |
| Beets | — | — | Apr 25 – May 23 | Jul 15 – Jul 29 |
| Potatoes | — | — | Apr 25 – May 16 | — |
| Swiss Chard | — | — | May 2 – May 30 | Jul 15 – Jul 29 |
| Cilantro | — | — | May 2 – May 23 | Jul 29 – Aug 19 |
| Green Beans | — | — | May 23 – Jun 13 | Jul 8 – Jul 22 |
| Sweet Corn | — | — | May 23 – Jun 6 | — |
| Sweet Potatoes | — | May 30 – Jun 20 | — | — |
| Garlic | — | — | — | Sep 9 – Oct 14 |
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 Winifred, MT weather station, 14 km away (elevation 3,245 ft (989 m)).
Frost dates near Winifred
- Lloyd May 23 · Sep 23
- Roy May 14 · Sep 24
- Hilger May 14 · Sep 28
- Zortman May 18 · Sep 23
- Hays May 18 · Sep 23
- Denton Jun 1 · Sep 11
- Lewistown May 14 · Sep 28
- Coffee Creek Jun 1 · Sep 11
- Forest Grove May 19 · Sep 25
- Grass Range May 20 · Sep 24
Frequently asked questions
When is the last frost in Winifred, MT?
The median last spring frost in Winifred, MT is May 16. There is still about a 10% chance of frost after May 30, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Winifred, MT?
The median first fall frost is September 23, with about a 10% chance of frost before September 9.
How long is the growing season in Winifred, MT?
About 130 days between the median last spring frost and first fall frost.
What planting zone is Winifred, MT?
Winifred, MT is in USDA hardiness zone 4b.