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USDA Hardiness Zone 7a

Frost Dates for 98951 — Wapato, Washington

Averages from Wapato, Wa US, the nearest reporting station, 2.7 miles away.

Plant tender crops after April 21, and expect the first autumn freeze around October 15. That leaves about 176 frost-free days.

Last spring frost
April 21

50% probability

First fall frost
October 15

50% probability

Growing season
176 days

frost-free

Hardiness zone
7a

0 to 5°F annual low

First snow
December 6

median, 1991–2020

Last snow
February 1

median, 1991–2020

Winters with snow
100%

19 of 19 observed

Snow per year
20.4"

NOAA normal

When it snows in Wapato, Washington

The first measurable snow (0.1 inch or more) in Wapato, Washington usually arrives around December 6, and the last of the season around February 1. Those are the middle dates across the winters of 1991–2020 at Wapato, Wa US: half of years saw snow earlier, half later. Every one of those winters saw snow.

For a gardener, snow matters less than frost: a light snow on frozen ground changes nothing, while a hard frost on an unprotected bed ends the season. Use the frost dates above for planting and the snow dates for getting hoses drained, mulch down and tender pots indoors.

Planting calendar for 98951

What to do and when, based on the frost normals for Wapato, Washington
WhenWhat to do
February 10 – February 24

Start peppers and aubergines indoors

They need eight to ten weeks under lights before they can go out.

February 24 – March 10

Start tomatoes indoors

Six to eight weeks gives a transplant big enough to set fruit early.

March 24 – April 7

Sow peas, spinach, lettuce, radish outdoors

These tolerate light frost and prefer to germinate in cool soil.

April 21 onward

Transplant tomatoes, peppers, basil, squash, cucumbers

The average last freeze has passed — still watch the actual forecast.

by July 23

Sow the autumn crop of carrots, beets and brassicas

They need about twelve weeks to size up before growth stops.

by October 1

Harvest tender crops, or be ready to cover them

A first freeze two weeks early is well within normal variation.

October 15 onward

Plant garlic, mulch beds, lift tender bulbs

Garlic wants a cold spell; bare soil loses structure over winter.

What these dates mean

Wait until after April 21 to put tender plants — tomatoes, peppers, basil, squash — in the ground. That is the date by which half of years in Wapato, Washington are past their last freeze. Harvest before October 15, which leaves roughly 176 frost-free days.

ZIP 98951 sits in USDA hardiness zone 7a, meaning the average coldest night of the year falls between 0 to 5°F. Zone decides what survives the winter; frost dates decide when to plant each spring. They are different questions, and a plant can pass one and fail the other.

These are thirty-year NOAA averages for 1991–2020, not a forecast. Any individual year can frost two to three weeks either side of these dates, so check the actual forecast before planting out.

Other zone 7a ZIP codes in Washington