Frost Dates for 63040 — Wildwood, Missouri

Half of springs at St Louis Sprt Of S L Airport, MO see their last 32°F night by April 12; only one in ten is past it by March 28, and one in ten still has one after April 27. Planting tender crops after April 19 leaves a 30% risk of a frost on them, after April 22 20%, and after April 27 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 54% of the 158 Missouri stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 23 in half of years, as early as October 11 one year in ten, and holds off past November 5 one year in ten. A hard freeze of 28°F follows 11 days later, around November 3; in spring the one-in-ten date for 28°F is April 17, 10 days before the 32°F one. The freeze-free season lasts 193 days in a typical year, shorter than at 55% of the 158 Missouri stations; it reaches 213 days one year in ten and falls short of 172 one year in ten. On average 105 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 12 days longer, to about April 24, and return around October 14. Severe cold of 16°F or below comes every winter, usually between December 7 and March 2.

July is the warmest month at St Louis Sprt Of S L Airport, MO, averaging 90°F by day and 68°F at night; January is the coldest at 41°F and 22°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 81% of years.

Warmth for growing adds up to 4,209 growing degree days a year (base 50°F), more than at 70% of the 158 Missouri stations. 38% of them (1,585) have built up by the end of June, and July adds the most, 891. Precipitation totals 39.8 inches a year, most in April (4.6") and least in February (2.0"); May to September bring 47% of it.

The nearest other station, St Charles 7 SSW, MO, 9 miles northeast of Wildwood, has a last frost 8 days earlier (April 4), a first frost 6 days later (October 29), a season 13 days longer.

The first measurable snow (0.1 inch or more) in Wildwood usually arrives around December 5, and the last of the season around March 8. Those are the middle dates across the winters of 1991–2020 at Weldon Spring NWS, MO, 9.2 miles away: half of years saw snow earlier, half later. Snow fell in 96% of those winters. The last 32°F night of spring typically comes 35 days after the last snow.

ZIP 63040 is 6 miles from St Louis Sprt Of S L Airport, MO, which stands at 462 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 5 other ZIP codes share the station; its figures are presented in full for 63005 (Chesterfield). The 2023 USDA Plant Hardiness Zone Map lists ZIP 63040 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.