Frost dates for Mc Henry WG Stratton L&D, Illinois
Half of years have their last spring frost by May 1, but 1 year in 10 still frosts after May 19.
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
- May 19
- 1 year in 5
- May 13
- 3 years in 10
- May 8
- 2 years in 5
- May 4
- Half of years (the median)
- May 1
First fall freeze
How often the first freeze comes on or before each date.
- 1 year in 10
- September 27
- 1 year in 5
- October 2
- 3 years in 10
- October 5
- 2 years in 5
- October 9
- Half of years (the median)
- October 11
- Growing season
- about 162 days
- Hardiness zone nearby
- 5b
- Summer days
- a usual high of about 28 °C82 °F
- Lettuce and spinach run to seed
- June 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 ~-1 °C31 °F · low ~-11 °C13 °F · rain ~42 mm1.6 in
- February
- high ~1 °C35 °F · low ~-9 °C16 °F · rain ~40 mm1.6 in
- March
- high ~8 °C46 °F · low ~-3 °C26 °F · rain ~56 mm2.2 in
- April
- high ~15 °C59 °F · low ~3 °C37 °F · rain ~92 mm3.6 in
- May
- high ~21 °C70 °F · low ~8 °C47 °F · rain ~114 mm4.5 in
- June
- high ~27 °C80 °F · low ~14 °C57 °F · rain ~122 mm4.8 in
- July
- high ~29 °C84 °F · low ~16 °C62 °F · rain ~96 mm3.8 in
- August
- high ~28 °C82 °F · low ~15 °C60 °F · rain ~94 mm3.7 in
- September
- high ~24 °C76 °F · low ~11 °C51 °F · rain ~92 mm3.6 in
- October
- high ~17 °C63 °F · low ~4 °C40 °F · rain ~82 mm3.2 in
- November
- high ~9 °C48 °F · low ~-1 °C29 °F · rain ~60 mm2.4 in
- December
- high ~2 °C36 °F · low ~-7 °C19 °F · rain ~49 mm1.9 in
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, the Mc Henry WG Stratton L&D station (listed by NOAA as Mc Henry -WG Stratton L&D, USC00115493), at 42.31, -88.25. 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
53181, 53192, 60002, 60010, 60012, 60013, 60014, 60020, 60021, 60030, 60034, 60041…
+18 moreShow fewer
60042, 60046, 60047, 60050, 60051, 60060, 60071, 60072, 60073, 60081, 60084, 60097, 60102, 60110, 60118, 60136, 60156, 60192.
Nearby stations
The nearest stations and how their last-frost dates compare. Together they show how frost varies across your area.
- Chicago Botanic Garden, IL, last frost by April 26
- Lisle-Morton Arboretum, IL, last frost by April 28
- Aurora, IL, last frost by April 19
- Racine Batten Airport, WI, last frost by April 24
- Rockford Greater Rockford Airport, IL, last frost by April 24
- Chicago Midway Airport, IL, last frost by April 11
Other stations in Illinois.
- Chicago Northerly Island, IL, last frost by April 10
- Park Forest, IL, last frost by April 23
- Hennepin Wtr Trmt Plt, IL, last frost by April 24
- Congerville 2 NW, IL, last frost by April 21
- Peoria Greater Peoria Airport, IL, last frost by April 16
- Rantoul, IL, last frost by April 21
- Aledo, IL, last frost by April 22
- Danville, IL, last frost by April 21
When do I plant? · Where the dates come from
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