Weather StoryAlmanac, microseasons, and the day's weather story.

St. John, Missouri Weather

Cicadas claim the scorching afternoon. Day 14 of summer. Read this microseason across nine climate regions →

St. John weather forecast — hour by hour, 7-day outlook, NOAA radar

St. John, MO
Saturday, July 4 at 10:43 AM
88
°
Clear
Feels like
95°
Humidity
57%
Wind
8 mph
Sunrise
12:42 AM
Sunset
3:29 PM
St. John, MO
Hour by hour · 24h
24-Hour ForecastSt. John, MO: 24-hour forecast. Temperatures range from 72 to 94 degrees Fahrenheit.
L 72°H 94°
St. John, MO
7-day forecast
  1. Today
    Jul 4
    Overcast
    19%
    —
    94°77°—
  2. Sunday
    Jul 5
    Light Showers
    28%
    0.33″
    81°72°-13°
  3. Monday
    Jul 6
    Overcast
    28%
    —
    90°70°+9°
  4. Tuesday
    Jul 7
    Overcast
    —
    —
    87°70°-3°
  5. Wednesday
    Jul 8
    Overcast
    10%
    —
    96°71°+9°
  6. Thursday
    Jul 9
    Light Drizzle
    31%
    —
    97°78°+1°
  7. Friday
    Jul 10
    Thunderstorm
    46%
    —
    92°74°-5°
St. John, MO
Next 24 hours · Warm now
HOT 90°65°83°100°6a12p6p12anow 86°high 94°low 72°PRECIP %
St. John, MO
Anemometer · 24h winds · from true
NESW
From · True
WSW
252° · veering 41°
Direction
WSW
252°
Sustained
8
mph
Gust
13
mph
Peak 24h
15
avg 6
Beaufort · 3 · GENTLE BRZ
0
CALM
<1
1
LIGHT AIR
1–3
2
LIGHT BRZ
4–7
3
GENTLE BRZ
8–12
4
MOD BRZ
13–18
5
FRESH BRZ
19–24
6
STRONG BRZ
25–31
7
NEAR GALE
32–38
24h · sust vs gust · mph
avg 6 · pk 15 @ 2:00p
0102030MPHB1B2B3B4B5B6-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 275SUSTGUST
−24h−18h−12h−6hnow
Light breeze veering 41° from the wsw.
St. John, MO
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
993.5
+1.5 mb in 3h · rising · 29.34 inHg
Now
993.5
mb
3h
+1.5
mb
12h
+1.0
mb
24h
-2.3
mb
Regime · STORM
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 992–996
9859909951000STORM|RAIN-21h-18h-15h-12h-9h-6h-3h-24hNOW995.9991.8993.6
−24h−18h−12h−6hnow
The low is filling — pressure climbing out of storm territory.
St. John, MO
Air quality
49
AQI
Good
→+1 in 6h

AQI 49 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 11.5 µg/m³, PM10 at 12.4 µg/m³ — typical background levels with no transport signature.

OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.

PM 2.5DRIVERGood
11.5μg/m³
PM 10Good
12μg/m³
NO₂Good
5μg/m³
OzoneModerate
99μg/m³
UV IndexModerate
4.0

What's driving it

Ozone × UV × Sky

Ozone at AQI 47. Overcast through the UV peak window (cloud cover ~69%) — afternoon ozone should stay flat.

Present
AQI 47
UV peak
5.7 at 1 PM
Sky at peak
overcast
Projected peak
AQI 18

PM × Wind × Precip

PM2.5 at 11.5 µg/m³, PM10 at 12.4 µg/m³ — typical background levels with no transport signature.

PM2.5/PM10
0.93
Wind
light
Recent rain
0h in last 6h
Pattern
background

Trends

Seven days of AQI and PM2.5.

Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).

7-DAY AQI TREND50100SATSUNMONTUEWEDTHUFRISAT7-DAY PM2.5 TREND · μg/m³330
St. John, MO
Sky cover · visibility · 24h
Cloud cover
4%
CLEAR
100%0%−24h−18h−12h−6hnow
Visibility
64.2mi
UNLIMITED
76 mi0 mi−24h−18h−12h−6hnow
Earth · GOES-19 ABI
Full Disk · Visible · GeoColor
GOES-19 full disk Visible · GeoColor
True-color daytime, blue/IR sandwich at night
15:43 UTC · St. John, MO · NOAA NESDIS / STAR · up to 10848 px
Continental US · GOES-19 ABI
CONUS Sector · Visible · GeoColor
GOES-19 CONUS Visible · GeoColor
Daytime true-color, blue-light/IR sandwich at night
15:43 UTC · St. John, MO · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
St. John, MO
Satellite · infrared · animated
St. John, MO
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
St. John, MO
Almanac · Saturday, July 4
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
Civil dawn
5:11 AM
Sunrise
12:42 AM
Daylight
14h 47m
Sunset
3:29 PM
Civil dusk
9:02 PM
Planting note
Harvest early potatoes. Begin drying onions on the surface.
St. John, MO
The moon
Waning Gibbous
80% illuminated
Moonrise
10:54 PM
Moonset
10:09 AM
In sign
♓︎ Pisces
St. John, MO
Microseason
Jul 1–5

Cicadas claim the scorching afternoon

bird
Jan 151% of the yearDec 31

Read this microseason across nine climate regions →

St. John at a glance

  • Today vs. normal: 15°F above the seasonal normal for this latitude
  • Last frost: April 8 (climatological average for this latitude)
  • Microseason: Jul 1–5
  • Planting window: Harvest early potatoes. Begin drying onions on the surface.

16-Day Forecast — St. John

  1. Sat94°77°19%
  2. Sun81°72°28%
  3. Mon90°70°28%
  4. Tue87°70°5%
  5. Wed96°71°10%
  6. Thu97°78°31%
  7. Fri92°74°46%
  8. Sat90°76°22%
  9. Sun81°66°7%
  10. Mon80°61°6%
  11. Tue81°64°10%
  12. Wed88°68°10%
  13. Thu86°70°10%
  14. Fri82°70°9%
  15. Sat88°73°14%
  16. Sun93°75°16%

Forecast data from Open-Meteo (CC BY 4.0).

Right now in the garden

Peak growing season

As of July 4, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.

SPC Convective Outlook

Storm Prediction Center — St. John

SPC has placed St. John in the Slight Risk category for severe thunderstorms today.

  • TODAYSLGTSlight Risk
  • TOMORROWTSTMGeneral Thunderstorms
  • DAY 3TSTMGeneral Thunderstorms

Scattered severe storms possible. A few tornadoes, hail, and damaging wind gusts possible.

Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.

January 1–5: Frost quiets the live oaks.January 6–10: Still water thickens with ice.January 11–15: Springs begin to move beneath ice.January 16–20: Cardinal dawn calls grow bolder.January 21–25: Late January thaw pulses.January 26–31: Last freeze locks the land.February 1–5: February's lengthening light.February 6–10: Warming winds thaw the margin.February 11–15: Magnolia blooms break the gray.February 16–20: Mockingbirds resume the dawn chorus.February 21–25: Rain replaces the last snow.February 26–28: Mist clings to greening valleys.March 1–5: The green pulse awakens.March 6–10: Hibernators emerge to call.March 11–15: Dogwood and redbud ignite.March 16–20: Swallowtails emerge from winter silk.March 21–25: Light crowns the dogwood canopy.March 26–31: Redbud cascades over the thaw.April 1–5: Thunder announces the wet season.April 6–10: Barn swallows carve the warming sky.April 11–15: Magnolia blooms and falls in a breath.April 16–20: First rainbows arch over thunderheads.April 21–25: Reeds push through marsh water.April 26–30: Frost retreats; seedlings rise free.May 1–5: Warblers flood the canopy in waves.May 6–10: Tulip poplar lights the forest crown.May 11–15: Shad pulse upstream through rapids.May 16–20: Roses open on the Piedmont edge.May 21–25: Fireflies scout the humid dusk.May 26–31: Frog choruses rise from every wetland.June 1–5: Fireflies pulse through the magnolias.June 6–10: Kudzu climbs deeper into green.June 11–15: Sun climbs to its northern throne.June 16–20: Heat settles and the rain begins.June 21–25: The longest day turns toward shadow.June 26–30: Fireflies drift through Spanish moss.July 1–5: Cicadas claim the scorching afternoon.July 6–10: Thunderheads boil and break at dusk.July 11–15: Thunder builds each drowsy afternoon.July 16–20: Cicadas claim the long noon.July 21–25: Dog days drape the earth in haze.July 26–31: Katydids begin their rasping chorus.August 1–5: Dusk arrives one minute earlier each night.August 6–10: Meteorological summer's turning page.August 11–15: Cool winds gather at the margins.August 16–20: Dog-day cicadas rise.August 21–25: Heat breaks in creek beds.August 26–31: Monarchs gather strength.September 1–5: Harvests begin in earnest.September 6–10: Dew beads on resurrection fern.September 11–15: Raptors trail the thermals.September 16–20: Day and dark find balance.September 21–25: Thunder quiets the land.September 26–30: Insects retreat below.October 1–5: Swamp waters recede.October 6–10: Maples ignite the ridge.October 11–15: Asters crown the meadows.October 16–20: Crickets sing at dusk.October 21–25: Frost paints the garden.October 26–31: Light rains whisper down.November 1–5: Sweetgum Turns Crimson.November 6–10: Camellia Blooms Break Through.November 11–15: Earth Stiffens Underfoot.November 16–20: Bare Limbs Hold the Light.November 21–25: First Frost Grips the High Ground.November 26–30: North Wind Strips the Last Leaves.December 1–5: Darkness Falls Before Dinner.December 6–10: Winter Locks the Land.December 11–15: Wildlife Retreats to Shelter.December 16–20: Ice Edges Deepen Inward.December 21–25: The Sun Begins its Return.December 26–31: The Year Turns in Silence.🌱February 14 — First skunk-cabbage spathes thaw their way up☀️March 20 — Spring equinox — day and night balance🌸April 5 — Cherry blossoms peak in the parks🐦May 10 — Warbler migration peaks along the coast✨May 25 — First fireflies scout the meadows at dusk🌞June 21 — Summer solstice — longest day🦗July 25 — Peak cicada chorus in the afternoons🌊August 18 — Warmest sea-surface temperatures of the year🍂September 22 — Autumn equinox — the slow turn❄️October 25 — First widespread frost in the suburbs🍁November 10 — Peak leaf color across the Hudson Valley🌙December 21 — Winter solstice — longest night

Microseason · July 1–5

Cicadas claim the scorching afternoon

Dog-day cicadas emerge in waves, their rasp dominating every sunny hour; heat peaks above 90 degrees daily.

Day 185 of 365 · Wedge 37 of 72

The solar year drawn as a wheel of 72 five-day windows. Each wedge is one microseason; the four colored arcs mark winter, spring, summer, and autumn; the small icons sit at notable phenological events. The crimson pointer creeps clockwise as the year turns.

Planting calendar

MonthPlantHarvest
January——
February——
March——
Aprillettuce, peas, spinach, radishes—
Maylettuce, peas, spinach, radishes, tomatoes, peppers, beans, squashlettuce, peas, radishes
Junetomatoes, peppers, beans, squashlettuce, peas, radishes
Julytomatoes, peppers, beans, squashtomatoes, beans, summer squash
August—tomatoes, beans, summer squash
Septemberfall brassicas, garlic (overwinter), carrotstomatoes, beans, summer squash
Octoberfall brassicas, garlic (overwinter), carrotswinter squash, tomatoes (last)
November——
December——

A year in weather

St. John's warmest month is July (~81°F mean) and its coldest is January (~31°F). Rainfall peaks in May (4.4 inches) and bottoms out in January (2.1 inches).

MonthMean tempPrecipRainy days
January31°2.1″13
February35°2.3″12
March45°4.0″16
April57°4.3″15
May66°4.4″17
June75°4.2″15
July81°2.7″13
August80°2.9″13
September72°2.6″11
October60°2.8″11
November45°3.6″13
December34°3.0″12

Regional context

Per NOAA NCEI 1991-2020 normals, St. John runs from a 31°F January mean to 81°F in July, a 50°F seasonal spread, with near 39.1 inches of precipitation across about 161 wet days.

Rainfall in St. John stays even across the calendar: May tops out at 4.4 inches over 17.2 rainy days, and January still logs 2.1 inches across 12.7 — a narrow range for St. John. That lines St. John up with places like Charlack, MO, Sycamore Hills, MO and Bel-Ridge, MO, fed by overlapping storm tracks.

Once St. John passes mid-April, overnight freezes fade and peas, lettuce, spinach, and radishes can be sown. Tomatoes and peppers do best set out two weeks later in St. John, once nights clear the mid-40s°F. The season ends by mid-November in St. John, once hard frosts set back in. A creek-bottom lot in St. John can lag St. John's last frost 7-10 days behind a south slope.

Similar climates: Charlack, MO, Sycamore Hills, MO, Bel-Ridge, MO, Breckenridge Hills, MO, Woodson Terrace, MO.

Frequently asked

When does it freeze in St. John?
St. John's last spring frost lands near mid-April, and in St. John the first fall frost follows around mid-November.
What is the rainy season in St. John?
Rainfall in St. John peaks in May near 4.4 inches, out of about 39 inches annually.
What is the warmest month in St. John?
July is St. John's warmest month, averaging about 81°F.
What is the coldest month in St. John?
St. John bottoms out in January, with a mean near 31°F.
When can I start a vegetable garden in St. John?
Frost-hardy sowings begin at mid-April in St. John; warm-season starts follow two weeks on.
How many rainy days does St. John get?
St. John averages about 161 days with measurable rain or snow each year.
What hardiness zone is St. John?
St. John's USDA zone comes from its January mean (31°F); enter the ZIP on the USDA lookup for the number.
What is the 10-day forecast for St. John?
St. John's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
Will it rain this week in St. John?
See this week's day-by-day rain chances for St. John in the daily forecast above, and the next 24 hours in the hourly chart.
What is the weather like right now in St. John?
Current conditions for St. John and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
How often is the St. John forecast updated?
The St. John forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
When are sunrise and sunset in St. John?
Today's sunrise and sunset times for St. John are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
How accurate is the weather forecast for St. John?
The next few days in St. John's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.

Climate

St. John, Missouri occupies a humid subtropical zone, with January means near 31°F and July around 81°F — a 50°F swing.

Across the year, St. John collects about 39 inches of precipitation over roughly 161 days with measurable rain or snow.

The 50°F gap between St. John's summer and winter, at 38.7°N, shapes St. John's frost calendar.

All cities in Missouri →

Florissant, MO weather →

ZIP codes in St. John

  • 63114

Climate normals from the Open-Meteo Climate API. Köppen approximation from NOAA NCEI U.S. Climate Regions. See methodology for data sources, editorial rules, and corrections. Maintainer: Brian Tighe.