Weather in O'Fallon, Missouri
Roses open on the Piedmont edge. Day 59 of spring. Read this microseason across nine climate regions →
O'Fallon, MO
Sunday, May 17 at 1:42 AM
73
°
Clear
Feels like
78°
Humidity
86%
Wind
7 mph
Sunrise
5:49 AM
Sunset
8:09 PM
O'Fallon, MO
Hour by hour · 24h
67°
8p
65°
9p
64°
10p
62°
11p
63°
12a
61°
1a
60°
2a
59°
3a
60°
4a
60°
18%
5a
60°
25%
6a
60°
18%
7a
62°
13%
8a
64°
11%
9a
68°
10a
73°
11a
76°
12p
78°
1p
80°
2p
80°
3p
80°
4p
79°
5p
78°
6p
76°
7p
O'Fallon, MO
7-day forecast
- TodayMay 16Rain69%77°68°
- SundayMay 17Overcast—87°66°
- MondayMay 18Light Drizzle46%86°72°
- TuesdayMay 19Showers84%78°58°
- WednesdayMay 20Overcast65%65°48°
- ThursdayMay 21Light Drizzle12%63°49°
- FridayMay 22Overcast18%64°52°
O'Fallon, MO
Next 24 hours · Mild now
O'Fallon, MO
Anemometer · 24h winds · from true
From · True
SE
144° · backing 60°
Direction
SE
144°
Sustained
7
mph
Gust
14
mph
Peak 24h
20
avg 8
Beaufort · 2 · LIGHT 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
−24h−18h−12h−6hnow
O'Fallon, MO
Air quality
36
AQI
Good
- PM 2.5
- 8.0 μg/m³
- PM 10
- 8.8 μg/m³
- NO₂
- 7.4 μg/m³
- Ozone
- 65.0 μg/m³
- UV Index
- 0.0 Low
O'Fallon, MO
Almanac · Sunday, May 17
When the dew is on the grass, rain will never come to pass.
Civil dawn
10:21 AM
Sunrise
5:49 AM
Daylight
14h 20m
Sunset
8:09 PM
Civil dusk
1:40 AM
Planting note
Direct sow okra, melons, and southern peas. Thin carrot rows.
O'Fallon, MO
The moon
New Moon
0% illuminated
- Moonrise
- 10:56 AM
- Moonset
- 1:37 AM
- In sign
- ♉︎ Taurus
O'Fallon, MO
Microseason · 28 of 72
May 16–20
Roses open on the Piedmont edge
insect
O'Fallon at a glance
- Today vs. normal: 73°F — typical for the season
- Last frost: April 9 (climatological average for this latitude)
- Microseason: 28 of 72, May 16–20
- Planting window: Direct sow okra, melons, and southern peas. Thin carrot rows.
Right now in the garden
Warm-season window is open
As of May 17, the last spring frost has passed for most years. Transplant tomatoes, peppers, eggplants, basil, and cucurbits (cucumbers, squash, melons) now. Direct-sow beans and corn into warm soil.