Richland, MT frost dates
Last spring frostJun 5median date
First fall frostSep 2median date
Growing season89 daysfrost-free
Hardiness zone3bZone 3b
How Richland compares
- In 8 years out of 10, the last spring frost in Richland falls between May 22 and June 23, a 32-day window. The first fall frost falls between August 15 and September 17.
- The median last frost is 17 days later than the Montana median of May 19.
- Its 89-day growing season is longer than 4% of the 325 Montana places with a regular frost season (state median 125 days).
- The last frost is 19 days later than the zone 3b median of May 17. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 3b chart.
- The weather station records an average of 217 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 22 |
| 50% (median) | June 5 |
| 10% (safe for tender plants) | June 23 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 15 |
| 50% (median) | September 2 |
| 90% (late) | September 17 |
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 Richland, MT
Richland, MT frost dates — last frost Jun 5, first frost Sep 2, zone 3b. whenisthelastfrost.com
Crop
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Start indoors: Mar 13 to Mar 27Transplant outside: May 8 to May 22
Start indoors: Mar 27 to Apr 10Transplant outside: Jun 19 to Jul 3
Start indoors: Mar 27 to Apr 10Transplant outside: Jun 19 to Jul 3
Start indoors: Apr 10 to Apr 24Transplant outside: Jun 12 to Jun 26
Start indoors: Apr 10 to Apr 24Transplant outside: May 15 to May 29Sow outdoors: May 8 to Jun 12Plant for fall: Jul 8 to Aug 5
Start indoors: Apr 10 to Apr 24Transplant outside: May 8 to May 22Sow outdoors: May 8 to May 22Plant for fall: Jun 24 to Jul 15
Start indoors: Apr 10 to Apr 24Transplant outside: May 22 to Jun 5
Start indoors: Apr 10 to Apr 24Transplant outside: May 15 to May 29
Start indoors: Apr 10 to Apr 24Transplant outside: May 22 to Jun 5
Start indoors: Apr 24 to May 8Transplant outside: Jun 26 to Jul 10Sow outdoors: Jun 26 to Jul 10
Start indoors: Apr 24 to May 8Transplant outside: Jun 12 to Jun 26
Sow outdoors: Apr 24 to May 15
Sow outdoors: Apr 24 to May 15Plant for fall: Jul 8 to Jul 29
Sow outdoors: May 1 to Jun 12Plant for fall: Jul 22 to Aug 12
Start indoors: May 8 to May 15Transplant outside: Jun 19 to Jun 26Sow outdoors: Jun 12 to Jun 26
Start indoors: May 8 to May 15Sow outdoors: Jun 12 to Jun 26
Start indoors: May 8 to May 15Sow outdoors: Jun 12 to Jun 26
Start indoors: May 8 to May 15Transplant outside: Jun 19 to Jul 3
Sow outdoors: May 15 to Jun 12
Sow outdoors: May 15 to Jun 12
Sow outdoors: May 15 to Jun 5
Sow outdoors: May 22 to Jun 19
Sow outdoors: May 22 to Jun 12Plant for fall: Jul 8 to Jul 29
Sow outdoors: Jun 12 to Jul 3
Sow outdoors: Jun 12 to Jun 26
Transplant outside: Jun 19 to Jul 10
Plant for fall: Aug 19 to Sep 23
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Richland, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 13 – Mar 27 | May 8 – May 22 | — | — |
| Peppers | Mar 27 – Apr 10 | Jun 19 – Jul 3 | — | — |
| Eggplant | Mar 27 – Apr 10 | Jun 19 – Jul 3 | — | — |
| Tomatoes | Apr 10 – Apr 24 | Jun 12 – Jun 26 | — | — |
| Lettuce | Apr 10 – Apr 24 | May 15 – May 29 | May 8 – Jun 12 | Jul 8 – Aug 5 |
| Kale | Apr 10 – Apr 24 | May 8 – May 22 | May 8 – May 22 | Jun 24 – Jul 15 |
| Broccoli | Apr 10 – Apr 24 | May 22 – Jun 5 | — | — |
| Cabbage | Apr 10 – Apr 24 | May 15 – May 29 | — | — |
| Cauliflower | Apr 10 – Apr 24 | May 22 – Jun 5 | — | — |
| Okra | Apr 24 – May 8 | Jun 26 – Jul 10 | Jun 26 – Jul 10 | — |
| Basil | Apr 24 – May 8 | Jun 12 – Jun 26 | — | — |
| Peas | — | — | Apr 24 – May 15 | — |
| Spinach | — | — | Apr 24 – May 15 | Jul 8 – Jul 29 |
| Radishes | — | — | May 1 – Jun 12 | Jul 22 – Aug 12 |
| Cucumbers | May 8 – May 15 | Jun 19 – Jun 26 | Jun 12 – Jun 26 | — |
| Zucchini & Summer Squash | May 8 – May 15 | — | Jun 12 – Jun 26 | — |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 89 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 8 – May 15 | — | Jun 12 – Jun 26 | — |
| Melons & Watermelon Warning: Your frost-free season is about 89 days, which is tight for melons & watermelon (85+ days). Choose early varieties and use transplants or row covers. | May 8 – May 15 | Jun 19 – Jul 3 | — | — |
| Carrots | — | — | May 15 – Jun 12 | — |
| Beets | — | — | May 15 – Jun 12 | — |
| Potatoes | — | — | May 15 – Jun 5 | — |
| Swiss Chard | — | — | May 22 – Jun 19 | — |
| Cilantro | — | — | May 22 – Jun 12 | Jul 8 – Jul 29 |
| Green Beans | — | — | Jun 12 – Jul 3 | — |
| Sweet Corn Warning: Your frost-free season is about 89 days, which is tight for sweet corn (80+ days). Choose early varieties and use transplants or row covers. | — | — | Jun 12 – Jun 26 | — |
| Sweet Potatoes Warning: Your frost-free season is about 89 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 19 – Jul 10 | — | — |
| Garlic | — | — | — | Aug 19 – Sep 23 |
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 Opheim 12 Sse, MT weather station, 15 km away (elevation 2,936 ft (895 m)).
Frost dates near Richland
- Larslan Jun 5 · Sep 2
- Glentana Jun 5 · Sep 2
- Peerless May 28 · Sep 6
- Opheim Jun 1 · Sep 7
- Frazer May 12 · Sep 24
- Saint Marie May 13 · Sep 27
- Scobey May 28 · Sep 6
- Nashua May 12 · Sep 24
- Glasgow May 6 · Sep 30
- Vandalia May 15 · Sep 26
Frequently asked questions
When is the last frost in Richland, MT?
The median last spring frost in Richland, MT is June 5. There is still about a 10% chance of frost after June 23, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Richland, MT?
The median first fall frost is September 2, with about a 10% chance of frost before August 15.
How long is the growing season in Richland, MT?
About 89 days between the median last spring frost and first fall frost.
What planting zone is Richland, MT?
Richland, MT is in USDA hardiness zone 3b.