When is the last frost in West Covina, CA?

The average last spring frost (50% probability of 32°F) in West Covina is around January 8, based on NOAA/NCEI 1991–2020 normals at the Pomona/fairplex, CA station (7.4 mi away). Half of years it falls outside that date, so wait 1–2 weeks past it before setting out frost-tender plants.

When is the first fall frost in West Covina?

The average first fall frost in West Covina, CA is around December 28, giving roughly a 354-day frost-free growing season.

What planting zone is West Covina, CA?

West Covina is in USDA plant hardiness zone 10a (average annual extreme minimum temperature 30 to 35°F), from the 2023 USDA Plant Hardiness Zone Map.

What is the weather like in West Covina?

In West Covina, CA the warmest month is August (avg high 92.4°F) and the coldest is December (avg low 41.5°F). It averages about 14.5″ of precipitation a year.

Home › California › West Covina

West Covina, CA Planting Calendar & Frost Dates

USDA hardiness zone 10a · ZIP 91791 · elevation 305′ · NOAA & USDA data

West Covina is in USDA hardiness zone 10a (winters can dip to 30 to 35°F), with a growing season of about 354 days between the average last spring frost (January 8) and first fall frost (December 28). The warmest month is August (avg high 92.4°F); the coldest is December (avg low 41.5°F). It averages 14.5″ of precipitation a year. Start cool-season crops several weeks before the last frost; wait until after it for tomatoes, peppers and other tender crops.

Hardiness zone

10a

min temp 30 to 35°F

Last spring frost

January 8

avg (50% prob, 32°F)

First fall frost

December 28

avg (50% prob, 32°F)

Growing season

354 days

frost-free window

Warmest month

August

avg high 92.4°F

Month-by-month typical weather in West Covina

Average conditions from the NOAA/NCEI 1991–2020 U.S. Climate Normals at Pomona/fairplex, CA (7.4 mi away). Temperatures °F, precipitation & snow in inches.

Month	Avg high	Avg low	Mean	Precip (in)
January	67.9	43.1	55.5	2.9
February	67.3	44.5	55.9	4.2
March	72	47	59.5	2.1
April	75.8	49.6	62.7	1
May	78.4	54	66.2	0.2
June	84.3	57.2	70.8	0.1
July	90.3	62.3	76.3	0
August	92.4	62.7	77.5	0
September	88.7	60.4	74.6	0
October	80.5	53.9	67.2	1
November	73.5	47	60.2	0.7
December	66.9	41.5	54.2	2.3

What to plant when in West Covina

Crop	Season	What to do & when
Tomatoes	warm	Start seeds indoors: November 27 · Transplant out: January 15
Peppers	warm	Start seeds indoors: November 13 · Transplant out: January 22
Cucumbers	warm	Direct sow: January 15
Zucchini / squash	warm	Direct sow: January 15
Bush beans	warm	Direct sow: January 15
Sweet corn	warm	Direct sow: January 15
Basil	warm	Transplant out: January 15
Peas	cool	Sow (spring): December 4 · Sow (fall): November 2
Spinach	cool	Sow (spring): November 27 · Sow (fall): November 2
Lettuce	cool	Sow (spring): December 11 · Sow (fall): November 2
Kale	cool	Transplant (spring): December 18 · Sow (fall): October 19
Broccoli	cool	Transplant (spring): December 25
Carrots	cool	Sow (spring): December 18 · Sow (fall): October 19
Onions	cool	Transplant (spring): December 11
Potatoes	cool	Plant seed potatoes: December 25
Radishes	cool	Sow (spring): December 11 · Sow (fall): November 16

Dates are computed from West Covina's average frost dates using standard cool-/warm-season timing. They're a starting point — a cold spring, a warm microclimate, or a fast-maturing variety can shift them by a week or two.

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Gear that helps you plant on time

Some links below are Amazon affiliate links (tag theboringthin-20). If you buy through them we may earn a small commission at no extra cost to you — it keeps this almanac free. We only list generic, genuinely-useful categories.

Soil thermometer →Know when the ground is warm enough to sow — the honest signal, not the calendar.Seed-starting trays + dome →Start tomatoes & peppers indoors on the schedule below.Seedling heat mat →Warms the soil for faster, more even germination indoors.Floating row cover / frost cloth →Buys you 4–8°F to beat an early or late frost.Raised garden bed kit →Warms and drains faster in spring than in-ground soil.Garden gloves →Basic kit for transplant day.

Nearby cities in California

Covina, CA Glendora, CA Baldwin Park, CA La Puente, CA Diamond Bar, CA Pomona, CA El Monte, CA Monrovia, CA

Sources & method. Hardiness zone: 2023 USDA Plant Hardiness Zone Map (PRISM Climate Group, Oregon State University). Frost dates & growing season: NOAA/NCEI 1991–2020 U.S. Climate Normals, nearest station with published freeze normals — Pomona/fairplex, CA, 7.4 mi (confidence: high). Monthly weather normals: Pomona/fairplex, CA, 7.4 mi (confidence: high). ZIP centroid from U.S. Census 2023 ZCTA data. Frost dates are the 50%-probability date — half of years frost occurs outside the stated date. Nothing here is invented; where the nearest station is far, we say so. Last updated 2026-07-22.