Best days to paint a house exterior in St. Louis, MO this week
Here's the next 7 days for painting outside in St. Louis, checked hour by hour against the published thresholds. Below it: what St. Louis's 1991–2020 climate averages say about the months that usually work.
This week in St. Louis
Asking the sky…
Fairsky is not a substitute for official warnings. For warnings, go to weather.gov. Verdicts are guidance, not guarantees. Your product's label always wins.
When painting outside usually works in St. Louis
- On 1991–2020 averages, St. Louis has normal lows of 40°F or warmer and highs of 90°F or cooler, which fits standard exterior paint's 40°F minimum day and night, in April–October.
- Of those months, September averages the fewest days with 0.10" or more of rain (4.3), which matters because paint needs about 4 rain-free hours after the last coat.
- In March and November, afternoons are warm enough but normal lows dip below 40°F; finish early so the paint sets before the evening dew and chill.
| Month | Avg high | Avg low | Days ≥0.10" rain | Lows 40°F+, highs ≤90°F |
|---|---|---|---|---|
| January | 40° | 24° | 4.3 | – |
| February | 46° | 28° | 4.4 | – |
| March | 56° | 36° | 6.4 | – |
| April | 68° | 46° | 7.3 | Yes |
| May | 77° | 57° | 8.6 | Yes |
| June | 86° | 65° | 6.5 | Yes |
| July | 89° | 69° | 6.0 | Yes |
| August | 88° | 66° | 4.9 | Yes |
| September | 81° | 57° | 4.3 | Yes |
| October | 69° | 46° | 5.4 | Yes |
| November | 55° | 36° | 5.3 | – |
| December | 44° | 29° | 5.2 | – |
Station: Cahokia St Louis Airport (NOAA NCEI USW00003960), about 7 km from central St. Louis. “Rain days” count days with 0.10" or more of precipitation. “Lows 40°F+, highs ≤90°F” checks the monthly averages only; any given week can be warmer, colder or wetter.
The rules we check
- Needs 4 hours in a row of daylight.
- Air at least 40°F (35–39°F is borderline).
- No hotter than 90°F.
- Air at least 5°F above the dew point, so surfaces don't stay damp.
- Humidity at or below 85%. (Fairsky default: no source gave a number)
- Wind at or under 15 mph. (Fairsky default: no source gave a number)
- Gusts at or under 25 mph. (Fairsky default: no source gave a number)
- Rain chance at or below 20%. (Fairsky default: no source gave a number)
- No rain in the 6 hours before, so surfaces are dry.
- No rain for 4 hours after you finish.
- The first night's low stays at 40°F or warmer. (Fairsky default: no source gave a number)
Your product's label always wins. Labels differ by product; in the app you can enter your label's temperature range and rain-free hours, and the verdict uses them instead.
Sources: Benjamin Moore exterior paint data sheet · Sherwin-Williams Duration exterior data sheet
More home and yard jobs in St. Louis
- Stain a deckDeck and fence stain: 50–90°F, dry wood, 24 rain-free hours after.
- Pour concreteConcrete: 40–85°F, no rain for 24 hours, no freezing for 48.
- Spray weedsWeed killer: 3–10 mph wind, 45–85°F, 4 rain-free hours after.
- Apply pre-emergentCrabgrass pre-emergent: before soil holds 55°F (about 200 GDD), then water it in.
- Plant grass seedCool-season grass seed: soil about 50–65°F, highs 60–80°F, no washout rain.
- Seal a drivewayAsphalt sealcoat: 55°F and rising, 50°F overnight, 36 rain-free hours.
- Cover plants for frostFrost watch: cover at 34°F, or 36°F on clear, calm nights; 28°F is a hard freeze.
The app covers 47 activities in all, from mowing to a round of golf: see every activity and its rules.
Paint a house exterior in nearby cities
- Indianapolis, IN230 miles away
- Kansas City, MO238 miles away
- Memphis, TN240 miles away
- Louisville, KY242 miles away
- Nashville, TN253 miles away
- Chicago, IL262 miles away
All paint a house exterior cities: Paint a house exterior, by city · Home and yard in Missouri
Questions
What's the best month to paint a house exterior in St. Louis?
On 1991–2020 averages, September usually fits best in St. Louis. Any given week can still be wrong for it, which is what the live verdict above is for.
How is this verdict made?
We take the National Weather Service hourly forecast for St. Louis and check each hour against the thresholds listed above. The result is guidance, not a guarantee; your product's label always wins.
Is it too cold to paint outside in St. Louis today?
Standard exterior latex usually needs air and surface at 40°F or warmer, through the first night, and at least 5°F above the dew point. The verdict above checks all of it for St. Louis.
Fairsky is not a substitute for official warnings. For warnings, go to weather.gov.
Live forecasts: National Weather Service / NOAA (public domain), fetched by your browser. Climate averages: NOAA NCEI U.S. Climate Normals, 1991–2020 (public domain). Activity thresholds: product data sheets, ACI and university extension guidance, linked on each page; your product’s label wins.