Frost dates for Dearborn, Michigan
Half of years have their last spring frost by May 1, but 1 year in 10 still frosts after May 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
- May 18
- 1 year in 5
- May 12
- 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
- October 1
- 1 year in 5
- October 6
- 3 years in 10
- October 9
- 2 years in 5
- October 12
- Half of years (the median)
- October 15
- Growing season
- about 166 days
- Hardiness zones nearby
- 6a, 6b
- Summer days
- a usual high of about 28 °C82 °F
- Lettuce and spinach run to seed
- June to August, 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 ~0 °C32 °F · low ~-8 °C18 °F · rain ~64 mm2.5 in
- February
- high ~2 °C35 °F · low ~-7 °C19 °F · rain ~58 mm2.3 in
- March
- high ~7 °C45 °F · low ~-3 °C26 °F · rain ~58 mm2.3 in
- April
- high ~15 °C58 °F · low ~3 °C37 °F · rain ~83 mm3.3 in
- May
- high ~21 °C70 °F · low ~9 °C47 °F · rain ~91 mm3.6 in
- June
- high ~26 °C79 °F · low ~14 °C58 °F · rain ~83 mm3.3 in
- July
- high ~29 °C84 °F · low ~17 °C62 °F · rain ~90 mm3.5 in
- August
- high ~28 °C82 °F · low ~16 °C61 °F · rain ~82 mm3.2 in
- September
- high ~24 °C75 °F · low ~12 °C53 °F · rain ~76 mm3 in
- October
- high ~17 °C62 °F · low ~5 °C42 °F · rain ~73 mm2.9 in
- November
- high ~9 °C48 °F · low ~0 °C32 °F · rain ~70 mm2.7 in
- December
- high ~3 °C37 °F · low ~-4 °C24 °F · rain ~62 mm2.4 in
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, the Dearborn station (listed by NOAA as Dearborn, USC00202015), at 42.32, -83.24. 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
48033, 48075, 48101, 48120, 48122, 48124, 48125, 48126, 48127, 48128, 48135, 48138, 48141, 48146, 48150, 48152, 48154, 48173, 48180, 48183, 48185, 48186, 48192, 48193, 48195, 48204, 48209, 48210, 48217, 48218, 48219, 48223, 48227, 48228, 48229, 48235, 48239, 48240, 48335, 48336.
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.
- Detroit City Airport, MI, last frost by April 21
- Grosse Pointe Farms, MI, last frost by April 29
- Pontiac Wastewater Treatment Plant, MI, last frost by April 26
- Linden Wastewater Treatment Plant, MI, last frost by May 3
- Toledo Metcalf Field, OH, last frost by April 20
- Jackson Reynolds Field, MI, last frost by May 1
Other stations in Michigan.
- Greenville 2 NNE, MI, last frost by May 18
- Kent City 2 SW, MI, last frost by May 14