Missouri weather and outdoor projects
Missouri has a continental climate with hot, humid summers and cold winters, and spring is stormy and often very wet. St. Louis and Kansas City both see summer highs in the 90s and winter nights well below freezing. The Ozarks in the south are a bit milder.
September and October are often the best months for exterior projects, with warm days and lower humidity. Spring can work between rain events, but watch for multi-day wet spells. Freeze-thaw cycles through winter make proper curing and sealing important for concrete driveways and steps.
Frost dates in Missouri
In St. Louis, the median last spring freeze (32°F) is around April 2 and the median first fall freeze is around November 4, a frost-free season of about 215 days.
In Kansas City, the median last spring freeze (32°F) is around April 13 and the median first fall freeze is around October 24, a frost-free season of about 193 days.
Frost dates matter for concrete, which must not freeze in its first 48 hours, for paint and caulk that need nights above their minimum, and for lawn care, since crabgrass preventer goes down as the soil warms in spring. See how late in fall you can stain, paint or seal.
Best time to stain a deck in Missouri
In St. Louis, the most reliable months are May–June and September–October. April and July–August can also work on the right days. December–February is too cold, with average highs around 44°F. In March and November, nights average about 37°F, too cold for the coating to dry and cure overnight. In April, nights average about 47°F, so finish early on mild days and check the overnight low. July–August is hot, with highs near 89°F, so start early and keep out of full afternoon sun.
In Kansas City, the most reliable months are May–June and September. April, July–August and October can also work on the right days. November–February is too cold, with average highs around 44°F. In March, nights average about 34°F, too cold for the coating to dry and cure overnight. In April and October, nights average about 45°F, so finish early on mild days and check the overnight low. July–August is hot, with highs near 88°F, so start early and keep out of full afternoon sun.
Check this week’s hour-by-hour verdict with the deck staining forecast.
Best time to paint outside in Missouri
In St. Louis, the most reliable months are April–June and September–October. March, July–August and November can also work on the right days. December–February is too cold, with average highs around 44°F. March and November are cool, with highs around 56°F, so choose the warmest afternoons. July–August is hot, with highs near 89°F, so start early and keep out of full afternoon sun.
In Kansas City, the most reliable months are May–June and September–October. March–April, July–August and November can also work on the right days. December–February is too cold, with average highs around 41°F. March and November are cool, with highs around 54°F, so choose the warmest afternoons. In April, nights average about 44°F, so finish early on mild days and check the overnight low. July–August is hot, with highs near 88°F, so start early and keep out of full afternoon sun.
Check this week’s hour-by-hour verdict with the exterior painting forecast.
Best time to pour concrete in Missouri
In St. Louis, the most reliable months are April–October. November–March averages about 17 nights a month at or below 32°F, so fresh concrete needs blankets or heated enclosures.
In Kansas City, the most reliable months are May–September. April and October can also work on the right days. November–March averages about 20 nights a month at or below 32°F, so fresh concrete needs blankets or heated enclosures. April and October bring about 3 freezing nights a month, so pick a mild spell and keep curing blankets on hand.
Check this week’s hour-by-hour verdict with the concrete pouring forecast.
Best time to seal a driveway in Missouri
In St. Louis, the most reliable months are May–September. April and October can also work on the right days. November–March is too cold, with average highs around 49°F. In April and October, nights average about 48°F, so finish early on mild days and check the overnight low.
In Kansas City, the most reliable months are May–September. April and October can also work on the right days. November–March is too cold, with average highs around 47°F. April and October are cool, with highs around 66°F, so choose the warmest afternoons.
Check this week’s hour-by-hour verdict with the driveway sealing forecast.
Best time to fertilize or treat a lawn in Missouri
In St. Louis, the most reliable months are April–June and September–October. March, July–August and November can also work on the right days. December–February is too cold, with average highs around 44°F. March and November are cool, with highs around 56°F, so choose the warmest afternoons. July–August is hot, with highs near 89°F, so start early and keep out of full afternoon sun.
In Kansas City, the most reliable months are April–June and September–October. March, July–August and November can also work on the right days. December–February is too cold, with average highs around 41°F. March and November are cool, with highs around 54°F, so choose the warmest afternoons. July–August is hot, with highs near 88°F, so start early and keep out of full afternoon sun.
Check this week’s hour-by-hour verdict with the lawn fertilizer forecast.
How the weather differs across Missouri
| Place | Hottest month avg high | Coldest month avg low | Rain per year | Last spring freeze | First fall freeze |
|---|---|---|---|---|---|
| St. Louis | 90°F | 24°F | 42 in | April 2 | November 4 |
| Kansas City | 88°F | 20°F | 39 in | April 13 | October 24 |
Of the places above, St. Louis has the most good months for staining, painting and concrete combined (16 job-months), and Kansas City has the fewest (12). If you live between them, expect something in between, and higher ground to be cooler with a shorter season.
Monthly weather in St. Louis
| Month | Avg high | Avg low | Wet days* | Rain | 3 PM humidity | Freezing nights |
|---|---|---|---|---|---|---|
| January | 40°F | 24°F | 5 | 2.6 in | 57% | 24 |
| February | 46°F | 28°F | 5 | 2.2 in | 51% | 19 |
| March | 57°F | 37°F | 7 | 3.5 in | 46% | 10 |
| April | 68°F | 47°F | 8 | 4.7 in | 45% | 1 |
| May | 77°F | 58°F | 8 | 4.8 in | 49% | 0 |
| June | 86°F | 67°F | 7 | 4.5 in | 49% | 0 |
| July | 90°F | 71°F | 6 | 3.9 in | 49% | 0 |
| August | 88°F | 69°F | 5 | 3.4 in | 49% | 0 |
| September | 81°F | 61°F | 5 | 3.0 in | 47% | 0 |
| October | 69°F | 49°F | 6 | 3.1 in | 46% | 1 |
| November | 56°F | 37°F | 5 | 3.4 in | 50% | 9 |
| December | 45°F | 29°F | 5 | 2.5 in | 57% | 20 |
*Days with at least 0.1 inch of rain or melted snow. Freezing nights: average nights a month at or below 32°F. Humidity is calculated from NOAA hourly normal temperature and dew point at 3 PM.
Monthly weather in Kansas City
| Month | Avg high | Avg low | Wet days* | Rain | 3 PM humidity | Freezing nights |
|---|---|---|---|---|---|---|
| January | 38°F | 20°F | 3 | 1.2 in | 56% | 27 |
| February | 44°F | 24°F | 3 | 1.5 in | 51% | 22 |
| March | 55°F | 34°F | 5 | 2.4 in | 46% | 14 |
| April | 66°F | 44°F | 7 | 4.0 in | 47% | 3 |
| May | 75°F | 54°F | 8 | 5.3 in | 53% | 0 |
| June | 84°F | 64°F | 7 | 5.3 in | 55% | 0 |
| July | 88°F | 68°F | 6 | 4.6 in | 54% | 0 |
| August | 87°F | 66°F | 6 | 4.2 in | 53% | 0 |
| September | 79°F | 58°F | 6 | 4.0 in | 52% | 0 |
| October | 67°F | 46°F | 5 | 3.3 in | 48% | 2 |
| November | 54°F | 34°F | 4 | 2.0 in | 51% | 13 |
| December | 42°F | 24°F | 3 | 1.6 in | 57% | 25 |
Use the averages, then check the forecast
These ratings describe a typical month, not a particular week. A warm spell in a “poor” month can give you a good day, and a wet week can spoil a “good” one. Use this page to plan the season, then check the 7-day forecast for your ZIP code before you buy materials or book help. Each project forecast checks the hours after you finish too: overnight lows, dew and rain that would ruin fresh stain, paint, sealer or concrete.
About this data
Monthly temperatures, rain days, snowfall and freeze dates are NOAA National Centers for Environmental Information (NCEI) U.S. Climate Normals for 1991–2020 at ST LOUIS LAMBERT INTL AP, KANSAS CITY INTL AP. Ratings apply the same temperature limits as our forecasts (for example, 50°F or warmer for deck stain and driveway sealer, and no freezing nights for new concrete) to the average month. Your product label always takes priority.
Frequently asked questions
When is the best time to stain a deck in Missouri?
In St. Louis, May–June and September–October. In Kansas City, May–June and September. Look for at least 24 dry hours before and after, and nights above about 40°F. The deck staining forecast checks your exact week.
When is the last frost in Missouri?
St. Louis: around April 2; Kansas City: around April 13. These are median dates from NOAA 1991–2020 normals, so a freeze after them happens in about half of years. Low spots and valleys freeze later in spring.
Can you pour concrete in winter in Missouri?
Yes, but it needs cold-weather practices. St. Louis averages about 63 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 Missouri?
In St. Louis, May–September. In Kansas City, May–September. Most sealers need 50°F or warmer for 24 hours and a dry day after. See the driveway sealing forecast.