Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 53008 — Brookfield, WI

ZIP code 53008 (Brookfield, Waukesha County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is April 30 and the first fall frost October 14.

Where ZIP 53008 is

tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone5b−15 to −10 °F
Coldest night−26.1 to −23.3 °C
Last frostApr 30
First frostOct 14
2012 zone5b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Brookfield, WI…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Brookfield, WI

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 30median — 50% chance of a later frost
Safe for tender plantsMay 15only 10% chance of frost after
First fall frostOctober 14median — 10% chance by Sep 28
Growing season164 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 19 and returns around October 25.

From the NOAA station Brookfield Wwtp, WI — 4 miles away, elevation 830 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 53008

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 19 – Apr 2
SpinachSow outdoors · Mar 19 – Apr 9
Broccoli, cabbageStart indoors · Feb 19 – Mar 5
Broccoli, cabbageTransplant · Apr 9 – Apr 23
Onion setsPlant outdoors · Apr 2 – Apr 16
PotatoesPlant outdoors · Apr 9 – Apr 23
LettuceSow outdoors · Apr 2 – Apr 16
Carrots, beetsSow outdoors · Apr 9 – Apr 23
TomatoesStart indoors · Mar 5 – Mar 19
TomatoesTransplant · May 7 – May 21
Peppers, eggplantStart indoors · Feb 19 – Mar 5
Peppers, eggplantTransplant · May 14 – May 28
BeansSow outdoors · May 7 – May 21
Sweet cornSow outdoors · May 7 – May 21
Cucumbers, squashSow outdoors · May 7 – May 21
Fall lettuce, spinachSow outdoors · Aug 19 – Sep 2
GarlicPlant cloves · Sep 30 – Nov 4
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 14) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 53008 came on Mar 30 — 14 days earlier than the 1991–2020 average (Apr 13).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 5b in Wisconsin

518 plants native to the lower 48 states, recorded in Wisconsin, and rated by the USDA to survive −15 °F or colder — the bottom of zone 5b. Each links to its USDA PLANTS profile.

Trees 49

Shrubs 93

Wildflowers & perennials 197

Grasses 159

Vines 5

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Brookfield, WI.

Soil in Brookfield, WI

The soil mapped at the center of ZIP 53008 is Mequon — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables
pH7.0neutral; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter3%moderate
Hydrologic groupCwater soaks in slowly
Farmland classPrime farmland if drainedUSDA classification

Map unit: Mequon silt loam, 1 to 3 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 53008; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Brookfield, WI

Summer high81 °Faverage high, July
Winter low12 °Faverage low, January
Hot days7days a year at 90 °F or more
Freezing nights149nights a year at 32 °F or less
Growing degree days2,550base 50 °F — the season’s usable heat
Longest day15 h 22 mindaylight on June 21
Shortest day9 h 00 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation35.9 inper year, rain and melted snow

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 28 °F, low 12 °F 28°12° JanFebruary: average high 32 °F, low 15 °F 32°15° FebMarch: average high 42 °F, low 25 °F 42°25° MarApril: average high 54 °F, low 35 °F 54°35° AprMay: average high 67 °F, low 47 °F 67°47° MayJune: average high 77 °F, low 56 °F 77°56° JunJuly: average high 81 °F, low 61 °F 81°61° JulAugust: average high 79 °F, low 60 °F 79°60° AugSeptember: average high 72 °F, low 51 °F 72°51° SepOctober: average high 59 °F, low 40 °F 59°40° OctNovember: average high 45 °F, low 29 °F 45°29° NovDecember: average high 33 °F, low 19 °F 33°19° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 1.59 in precipitation 1.6 JanFebruary: 1.56 in precipitation 1.6 FebMarch: 2.06 in precipitation 2.1 MarApril: 3.71 in precipitation 3.7 AprMay: 3.94 in precipitation 3.9 MayJune: 4.80 in precipitation 4.8 JunJuly: 3.82 in precipitation 3.8 JulAugust: 3.97 in precipitation 4.0 AugSeptember: 3.21 in precipitation 3.2 SepOctober: 3.09 in precipitation 3.1 OctNovember: 2.19 in precipitation 2.2 NovDecember: 1.96 in precipitation 2.0 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Brookfield Wwtp, WI (4 mi away); precipitation: Brookfield Wwtp, WI (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

All 3 ZIP codes in Brookfield → · Wisconsin planting zones →

Questions about 53008

What planting zone is ZIP code 53008?

ZIP code 53008 (Brookfield, WI) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Brookfield, WI?

The median last spring frost (32 °F) near 53008 is April 30; after May 15 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Brookfield Wwtp station.

When is the first frost in Brookfield, WI?

The median first fall frost near 53008 is October 14, giving a median frost-free growing season of 164 days.

When should I plant tomatoes in 53008?

Start tomato seeds indoors around Mar 5 – Mar 19 and set transplants outside around May 7 – May 21, one to three weeks after the median last frost.

How much rain and snow does 53008 get?

About 35.9 inches of precipitation a year (NOAA 1991–2020 normals, Brookfield Wwtp station).

How hot do summers get in Brookfield, WI?

The average high peaks at 81 °F in July, with about 7 days a year at 90 °F or more.

What kind of soil does 53008 have?

The USDA soil survey maps Mequon at the center of ZIP 53008: silt loam, somewhat poorly drained, pH about 7.0 (neutral).

Did spring come early in Brookfield, WI in 2026?

Spring leaf-out near 53008 came on Mar 30 in 2026, 14 days earlier than the 1991–2020 average (Apr 13), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Brookfield, WI?

Long-day onions: the longest day near 53008 is 15 h 22 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).