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

Planting zone for 53005 — Brookfield, WI

ZIP code 53005 (Brookfield, Waukesha County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is April 26 and the first fall frost October 18.

Where ZIP 53005 is

Outlined: the ZIP code area · 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 26
First frostOct 18
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 26median — 50% chance of a later frost
Safe for tender plantsMay 12only 10% chance of frost after
First fall frostOctober 18median — 10% chance by Oct 2
Growing season173 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 14 and returns around October 30.

From the NOAA station Mt Mary College, WI — 4 miles away, elevation 715 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 53005

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 15 – Mar 29
SpinachSow outdoors · Mar 15 – Apr 5
Broccoli, cabbageStart indoors · Feb 15 – Mar 1
Broccoli, cabbageTransplant · Apr 5 – Apr 19
Onion setsPlant outdoors · Mar 29 – Apr 12
PotatoesPlant outdoors · Apr 5 – Apr 19
LettuceSow outdoors · Mar 29 – Apr 12
Carrots, beetsSow outdoors · Apr 5 – Apr 19
TomatoesStart indoors · Mar 1 – Mar 15
TomatoesTransplant · May 3 – May 17
Peppers, eggplantStart indoors · Feb 15 – Mar 1
Peppers, eggplantTransplant · May 10 – May 24
BeansSow outdoors · May 3 – May 17
Sweet cornSow outdoors · May 3 – May 17
Cucumbers, squashSow outdoors · May 3 – May 17
Fall lettuce, spinachSow outdoors · Aug 23 – Sep 6
GarlicPlant cloves · Oct 4 – Nov 8
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 26) and first fall frost (Oct 18) 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 53005 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

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 93

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican hornbeam30 ft · blooms mid spring · low shade tolerance · to −34 °F

Wildflowers & perennials 197

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 159

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbeaked sedge4 ft · blooms late spring · low shade tolerance · to −38 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °FBebb's sedge3 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 5

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °FVirginia creeper1 ft · blooms late spring · medium shade tolerance · to −28 °F

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 53005 is Ozaukee — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables
pH6.7neutral; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter1.7%low — add compost
Hydrologic groupCwater soaks in slowly
Farmland classprime farmlandUSDA classification

Map unit: Ozaukee silt loam, high carbonate substratum, 2 to 6 percent slopes, eroded.

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 53005; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Brookfield, WI

Summer high83 °Faverage high, July
Winter low14 °Faverage low, January
Hot days17days a year at 90 °F or more
Freezing nights134nights a year at 32 °F or less
Growing degree days2,804base 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)
Precipitation33.8 inper year, rain and melted snow
Snowfall40 inper year; 58 days with snow on the ground

Average high and low, by month

0°10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 30 °F, low 14 °F 30°14° JanFebruary: average high 34 °F, low 17 °F 34°17° FebMarch: average high 44 °F, low 26 °F 44°26° MarApril: average high 56 °F, low 36 °F 56°36° AprMay: average high 68 °F, low 48 °F 68°48° MayJune: average high 78 °F, low 58 °F 78°58° JunJuly: average high 83 °F, low 63 °F 83°63° JulAugust: average high 81 °F, low 62 °F 81°62° AugSeptember: average high 74 °F, low 53 °F 74°53° SepOctober: average high 61 °F, low 42 °F 61°42° OctNovember: average high 47 °F, low 30 °F 47°30° NovDecember: average high 35 °F, low 21 °F 35°21° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 1.48 in precipitation, 11 in snowfall 1.5❄11 JanFebruary: 1.49 in precipitation, 9.9 in snowfall 1.5❄10 FebMarch: 1.79 in precipitation, 5.3 in snowfall 1.8❄5 MarApril: 3.71 in precipitation, 1.5 in snowfall 3.7❄2 AprMay: 3.73 in precipitation 3.7 MayJune: 4.84 in precipitation 4.8 JunJuly: 3.57 in precipitation 3.6 JulAugust: 3.68 in precipitation 3.7 AugSeptember: 3.02 in precipitation 3.0 SepOctober: 2.73 in precipitation 2.7 OctNovember: 2.05 in precipitation, 2 in snowfall 2.0❄2 NovDecember: 1.73 in precipitation, 9.8 in snowfall 1.7❄10 Dec

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

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

530085b
Brookfield, WI · <1 mi
531225b
Elm Grove, WI · 1 mi
532635b
Milwaukee, WI · 2 mi
530455b
Brookfield, WI · 3 mi
532265b
Milwaukee, WI · 3 mi
530075b
Butler, WI · 3 mi
532225b
Milwaukee, WI · 3 mi
532255b
Milwaukee, WI · 5 mi

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

Questions about 53005

What planting zone is ZIP code 53005?

ZIP code 53005 (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 53005 is April 26; after May 12 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Mt Mary College station.

When is the first frost in Brookfield, WI?

The median first fall frost near 53005 is October 18, giving a median frost-free growing season of 173 days.

When should I plant tomatoes in 53005?

Start tomato seeds indoors around Mar 1 – Mar 15 and set transplants outside around May 3 – May 17, one to three weeks after the median last frost.

How much rain and snow does 53005 get?

About 33.8 inches of precipitation a year and 40 inches of snowfall (NOAA 1991–2020 normals, Mt Mary College station).

How hot do summers get in Brookfield, WI?

The average high peaks at 83 °F in July, with about 17 days a year at 90 °F or more.

What kind of soil does 53005 have?

The USDA soil survey maps Ozaukee at the center of ZIP 53005: silt loam, moderately well drained, pH about 6.7 (neutral).

Did spring come early in Brookfield, WI in 2026?

Spring leaf-out near 53005 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 53005 is 15 h 22 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).