county: ST. LOUIS | location: ST CHARLES 7 SSW | lat: 38.686 | long: -90.523 | elev: 450 ft.
Temp Probability of observing a temperature as cold, or colder, later in the spring or earlier in the fall than the indicated date.
10% 30% 50% 70% 90%
(°F) spring fall season
length*
spring fall season
length*
spring fall season
length*
spring fall season
length*
spring fall season
length*
36 4/30 10/1 201 4/23 10/9 189 4/17 10/15 180 4/11 10/21 172 4/3 10/29 161
32 4/21 10/10 223 4/12 10/20 211 4/7 10/27 202 4/1 11/1 193 3/23 11/11 181
28 4/11 10/22 248 4/3 11/1 235 3/28 11/7 225 3/20 11/15 216 3/11 11/26 202
24 4/2 11/4 273 3/23 11/14 259 3/16 11/21 249 3/10 11/29 239 3/1 12/8 225

*Season length: number of days between last spring and first fall temperature thresholds, i.e. 36, 32, 28 and 24°F.