Minnesota weather and outdoor projects
Minnesota has cold winters and warm summers, with a short outdoor project season. The Twin Cities usually see their last spring freeze in late April or early May, while Duluth on Lake Superior stays cool much later into spring and has cooler summers.
June through early September is the best window for staining, painting and concrete. Spring can be wet, and fall cools quickly, with frosty nights by late September in the north. Concrete poured in the shoulder seasons often needs curing blankets. Freeze-thaw cycles and winter salt are hard on driveways and steps.
Frost dates in Minnesota
In Minneapolis–St. Paul, the median last spring freeze (32°F) is around April 23 and the median first fall freeze is around October 18, a frost-free season of about 176 days.
In Duluth, the median last spring freeze (32°F) is around May 13 and the median first fall freeze is around October 1, a frost-free season of about 140 days.
How Minnesota compares with other states
Minneapolis–St. Paul is tied for the 7th-longest deck staining season of the 50 state main stations (5 good months). Minneapolis–St. Paul has the 7th-most freezing nights of the 50 state main stations (147 a year). Minneapolis–St. Paul is tied for the 8th-fewest days at 90°F or hotter of the 50 state main stations (13 a year).
| Measure (Minneapolis–St. Paul) | Value | Rank, highest first |
|---|---|---|
| Deck staining season | 5 good months | 7th of 50 |
| Frost-free season | 176 days | 41st of 50 |
| Freezing nights | 147 a year | 7th of 50 |
| Rainy days | 62 a year with 0.1 in or more | 34th of 50 |
| Days at 90°F or hotter | 13 a year | 42nd of 50 |
| Summer afternoons | 50% humidity at 3 PM, June–August | 20th of 47 |
Best time to stain a deck in Minnesota
In Minneapolis–St. Paul, the most reliable months are May–September. October can also work on the right days (average highs Oct 58°F). November–March is too cold, with average highs around 33°F. In April, nights average about 38°F, too cold for the coating to dry and cure overnight. October is cool, with highs around 58°F, so choose the warmest afternoons.
In Duluth, the most reliable months are June–August. May and September can also work on the right days (average highs May 63°F, Sep 67°F). October–April is too cold, with average highs around 35°F. In May and September, nights average about 44°F, so finish early on mild days and check the overnight low.
Best time to paint outside in Minnesota
In Minneapolis–St. Paul, the most reliable months are May–September. April and October can also work on the right days (average highs Apr 57°F, Oct 58°F). November–March is too cold, with average highs around 33°F. April is cool, with highs around 57°F, so choose the warmest afternoons. In October, nights average about 41°F, so finish early on mild days and check the overnight low.
In Duluth, the most reliable months are June–September. May and October can also work on the right days (average highs May 63°F, Oct 53°F). November–April is too cold, with average highs around 32°F. In May, nights average about 41°F, so finish early on mild days and check the overnight low. October is cool, with highs around 53°F, so choose the warmest afternoons.
Best time to pour concrete in Minnesota
In Minneapolis–St. Paul, the most reliable months are May–September. October can also work on the right days (average highs Oct 58°F). November–April averages about 23 nights a month at or below 32°F, so fresh concrete needs blankets or heated enclosures. October brings about 6 freezing nights a month, so pick a mild spell and keep curing blankets on hand.
In Duluth, the most reliable months are June–September. May can also work on the right days (average highs May 63°F). October–April averages about 25 nights a month at or below 32°F, so fresh concrete needs blankets or heated enclosures. May brings about 4 freezing nights a month, so pick a mild spell and keep curing blankets on hand.
Best time to seal a driveway in Minnesota
In Minneapolis–St. Paul, the most reliable months are June–September. May can also work on the right days (average highs May 69°F). October–April is too cold, with average highs around 40°F. In May, nights average about 50°F, so finish early on mild days and check the overnight low.
In Duluth, the most reliable months are July–August. June and September can also work on the right days (average highs Jun 72°F, Sep 67°F). October–April is too cold, with average highs around 35°F. In May, nights average about 41°F, too cold for the coating to dry and cure overnight. In June, nights average about 50°F, so finish early on mild days and check the overnight low. September is cool, with highs around 67°F, so choose the warmest afternoons.
Best time to fertilize or treat a lawn in Minnesota
In Minneapolis–St. Paul, the most reliable months are May–September. April and October can also work on the right days (average highs Apr 57°F, Oct 58°F). November–March is too cold, with average highs around 33°F. April and October are cool, with highs around 57°F, so choose the warmest afternoons.
In Duluth, the most reliable months are May–September. October can also work on the right days (average highs Oct 53°F). November–April is too cold, with average highs around 32°F. October is cool, with highs around 53°F, so choose the warmest afternoons.
How the weather differs across Minnesota
| Place | Hottest month avg high | Coldest month avg low | Rain per year | Last spring freeze | First fall freeze |
|---|---|---|---|---|---|
| Minneapolis–St. Paul | 83°F | 9°F | 32 in | April 23 | October 18 |
| Duluth | 78°F | 2°F | 31 in | May 13 | October 1 |
Of the places above, Minneapolis–St. Paul has the most good months for staining, painting and concrete combined (15 job-months), and Duluth has the fewest (11).
Monthly weather in Minneapolis–St. Paul
| Month | Avg high | Avg low | Wet days* | Rain | 3 PM humidity | Freezing nights |
|---|---|---|---|---|---|---|
| January | 24°F | 9°F | 3 | 0.9 in | 65% | 31 |
| February | 29°F | 13°F | 3 | 0.9 in | 59% | 27 |
| March | 42°F | 25°F | 5 | 1.7 in | 51% | 24 |
| April | 57°F | 38°F | 6 | 2.9 in | 42% | 9 |
| May | 69°F | 50°F | 8 | 3.9 in | 44% | 1 |
| June | 79°F | 60°F | 8 | 4.6 in | 48% | 0 |
| July | 83°F | 65°F | 7 | 4.1 in | 50% | 0 |
| August | 81°F | 63°F | 6 | 4.3 in | 51% | 0 |
| September | 73°F | 54°F | 5 | 3.0 in | 50% | 0 |
| October | 58°F | 41°F | 5 | 2.6 in | 50% | 6 |
| November | 42°F | 28°F | 4 | 1.6 in | 58% | 21 |
| December | 29°F | 15°F | 3 | 1.2 in | 66% | 30 |
*Days with 0.1 inch of rain or more; column notes.
Monthly weather in Duluth
| Month | Avg high | Avg low | Wet days* | Rain | 3 PM humidity | Freezing nights |
|---|---|---|---|---|---|---|
| January | 20°F | 2°F | 3 | 0.9 in | 65% | 31 |
| February | 25°F | 6°F | 3 | 1.0 in | 59% | 28 |
| March | 36°F | 18°F | 4 | 1.5 in | 54% | 28 |
| April | 49°F | 30°F | 6 | 2.5 in | 47% | 19 |
| May | 63°F | 41°F | 7 | 3.4 in | 46% | 4 |
| June | 72°F | 50°F | 8 | 4.4 in | 54% | 0 |
| July | 78°F | 56°F | 7 | 3.9 in | 55% | 0 |
| August | 76°F | 55°F | 6 | 3.7 in | 56% | 0 |
| September | 67°F | 47°F | 7 | 3.5 in | 57% | 1 |
| October | 53°F | 36°F | 6 | 2.9 in | 56% | 11 |
| November | 37°F | 23°F | 5 | 2.0 in | 63% | 25 |
| December | 25°F | 10°F | 4 | 1.5 in | 69% | 31 |
Source: NOAA NCEI U.S. Climate Normals 1991–2020 for MINNEAPOLIS/ST PAUL AP, DULUTH. See how the ratings work and how late in fall you can stain, paint or seal.
Frequently asked questions
When is the best time to stain a deck in Minnesota?
In Minneapolis–St. Paul, May–September. In Duluth, June–August.
When is the last frost in Minnesota?
Minneapolis–St. Paul: around April 23; Duluth: around May 13.
Can you pour concrete in winter in Minnesota?
Yes, with cold-weather practices: Minneapolis–St. Paul averages about 87 freezing nights from December to February, so fresh concrete needs insulated blankets, a heated enclosure or an accelerated mix, and must not freeze in the first 48 hours. Many homeowners wait for spring.
What months are best for sealing a driveway in Minnesota?
In Minneapolis–St. Paul, June–September. In Duluth, July–August.