Frost dates for St Louis Sci Center, Missouri
Half of years have their last spring frost by April 1, but 1 year in 10 still frosts after April 18.
A frost date is really a percentile from 30 years of records at a nearby weather station: in about half of years a frost still comes after the median date. Both numbers are below, so you can choose the risk yourself.
The odds
Last spring frost
How often a frost still comes on or after each date.
- 1 year in 10
- April 18
- 1 year in 5
- April 11
- 3 years in 10
- April 7
- 2 years in 5
- April 4
- Half of years (the median)
- April 1
First fall freeze
How often the first freeze comes on or before each date.
- 1 year in 10
- October 24
- 1 year in 5
- October 28
- 3 years in 10
- October 31
- 2 years in 5
- November 2
- Half of years (the median)
- November 4
- Growing season
- about 218 days
- Hardiness zones nearby
- 6b, 7a
- Summer days
- a usual high of about 31 °C88 °F
- Lettuce and spinach run to seed
- May to September, in hot, long days (how we know)
Summer and rain
A growing garden needs about 25 mm1 in of water a week, rain and watering together. Here is what a normal month brings.
Month by month
- January
- high ~5 °C41 °F · low ~-4 °C25 °F · rain ~69 mm2.7 in
- February
- high ~8 °C46 °F · low ~-2 °C28 °F · rain ~58 mm2.3 in
- March
- high ~14 °C56 °F · low ~3 °C38 °F · rain ~92 mm3.6 in
- April
- high ~20 °C68 °F · low ~9 °C48 °F · rain ~123 mm4.8 in
- May
- high ~25 °C77 °F · low ~15 °C59 °F · rain ~124 mm4.9 in
- June
- high ~30 °C86 °F · low ~20 °C67 °F · rain ~120 mm4.7 in
- July
- high ~32 °C90 °F · low ~22 °C72 °F · rain ~107 mm4.2 in
- August
- high ~31 °C89 °F · low ~21 °C70 °F · rain ~95 mm3.7 in
- September
- high ~28 °C82 °F · low ~16 °C62 °F · rain ~87 mm3.4 in
- October
- high ~21 °C70 °F · low ~10 °C50 °F · rain ~81 mm3.2 in
- November
- high ~13 °C56 °F · low ~4 °C39 °F · rain ~94 mm3.7 in
- December
- high ~7 °C45 °F · low ~-1 °C30 °F · rain ~66 mm2.6 in
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, the St Louis Sci Center station (listed by NOAA as St Louis Sci Ctr, USC00237452), at 38.63, -90.27. These are that station’s own records, unshifted. The further your garden is from it, the less exactly they describe your ground. The planner finds the nearest station to your garden and lowers its confidence with distance, so no number is presented as if it were measured in your garden.
Cold air also pools in low ground on the clear, still nights when frost happens, so a hollow can freeze while a slope a few hundred feet away does not. No table can know that about your garden. A few seasons of your own logged frosts can.
ZIP codes nearest this station
62059, 62060, 62090, 62201, 62203, 62204, 62205, 62206, 62207, 62236, 62239, 62240, 63026, 63042, 63044, 63074, 63088, 63101, 63102, 63103, 63104, 63105, 63106, 63107, 63108, 63109, 63110, 63111, 63112, 63113, 63114, 63115, 63116, 63117, 63118, 63119, 63120, 63121, 63122, 63123, 63124, 63125, 63126, 63127, 63128, 63129, 63130, 63131, 63132, 63133, 63134, 63135, 63136, 63139, 63140, 63141, 63143, 63144, 63147, 63155.
What can I plant here, and when? ›
Nearby stations
The nearest stations and how their last-frost dates compare. Together they show how frost varies across your area.
- Weldon Spring NWS, MO, last frost by April 10
- Belleville SIU Rsch, IL, last frost by April 12
- Festus, MO, last frost by April 9
- Carlinville, IL, last frost by April 14
- Hillsboro, IL, last frost by April 13
- Carbondale Southern Il Airport, IL, last frost by April 9
Other stations in Missouri.
- Pleasant Hill, MO, last frost by April 8
- Kansas City Downtown Airport, MO, last frost by April 4