Glendale, AZ Frost Dates: Last Spring and First Fall Frost

Glendale gardeners can count on January 20 as the even-odds date for the last spring frost and December 15 as the even-odds date for the first fall frost, which adds up to 331 days without a freeze in a typical year.

Dates at even odds leave half of all years unprotected. The safer pair for Glendale is February 18 in spring, which only one year in ten passes, and November 28 in fall, which one year in ten arrives before. Glendale's season is 102 days longer than the 229 days median across the 100 cities on these pages, which puts it 9th for season length.

Behind every date on this page is one weather station, Youngtown (NOAA USC00029634), 7.7 miles north-west of Glendale's internal point in the Census Bureau's files and about 1,150 feet up.

Glendale's last spring frost, by chance

Frost is still possible on December 23 in nine winters out of ten and on January 20 in five; only one winter in ten sees a freeze as late as February 18.

The earliest and latest of these dates are 57 days apart, wider than for most of the 100 cities here. A freeze can still come 29 days after the typical date in Glendale, which is why the late date matters more here than in most places.

First fall frost in Glendale

NOAA's early fall date for Glendale is November 28, its even-odds date is December 15 and its late date is January 7; the first freeze has come by each of them in one, five and nine years out of ten.

The fall dates spread over 40 days, wider than for most cities on these pages. One year in ten brings the first freeze 17 days ahead of the typical date.

Glendale's frost-free season

A season this much longer than the middle of the pack gives Glendale more days for slow crops, as the fall planting dates below show. The gap between a typical year and a short one is 34 days, wider than for most cities on these pages. Count on 297 days, not 331 days, when a crop has little slack.

These figures are NOAA's own counts of freeze-free days across its simulated years, which is why they can differ a little from the days between the two typical dates. At Youngtown, 95.2% of years have a night at or below 32°F. In the rest there is no last or first frost to date.

28°F dates in Glendale

Light frost and hard freeze are well separated in Glendale. In fall the typical 28°F night comes on December 29, 14 days after the first 32°F frost on December 15; in spring the last one comes on January 3, 17 days before the last 32°F frost. Crops that tolerate light frost have that stretch to themselves. The late 28°F spring date, February 1, is the one that still catches blooms and young transplants one year in ten, and the early fall date, December 10, is when a hard freeze has arrived in one fall out of ten.

Using Glendale's frost dates in the garden

University of New Hampshire Extension sorts vegetables by how they cope with cold. Cool-season crops go out before the last frost: counting from January 20, cabbage transplants go in on December 23 and lettuce from December 23 to December 30. Tender crops wait until it has passed, with peppers going out on February 3 and beans sown on or after January 20. The University of New Hampshire Extension sheet gives peas no frost count at all; sow them as soon as the soil thaws.

Counting from the late date instead of the typical one adds 29 days before tender crops go out, a big difference in Glendale. Gardeners who cannot cover plants on a cold night should take the later date.

Fall crops are counted back from the first frost: NC State Extension's days to harvest plus University of Georgia Extension's harvest allowance of 18 days. All 34 crops in the fall planner have room in Glendale, with a last planting day no earlier than July. The slowest crop that still fits is parsnips, which needs 148 days before the early first frost and so must be in by July 3.

Worked example: the last day for fall broccoli in Glendale

Broccoli transplants need up to 80 days to reach harvest by NC State Extension's table, and University of Georgia Extension adds 18 days to harvest, so 98 days must pass before frost. In Glendale the last planting day is September 8 against the typical first frost on December 15, and August 22 against the early date on November 28.

17 days separate the two last days, enough that in Glendale the earlier one is worth following.

In spring the same family goes in earlier: counting from January 20, University of New Hampshire Extension puts cabbage transplants out on December 23, weeks ahead of the last frost.

About the Youngtown station

At 7.7 miles north-west, the station is some distance from Glendale, so parts of the city may not match its record.

Its elevation is about 1,150 feet. Of the 100 stations behind these pages, 27 sit higher and 72 lower. NOAA flags this station's record as standard, the code S, for the data behind its 50% last-frost value.

Because the Census file has no elevation for Glendale, we cannot say how far your yard is above or below this station. When yours is clearly higher or lower, open the nearby stations in the frost dates tool and favor the colder one.

How Glendale's frost dates compare

Glendale sits in a cluster: Phoenix, AZ is only 6.3 miles away, and the other two cities below are not much farther, so gaps in their dates come from local setting.

• Phoenix, AZ (6.3 miles, north-east): spring frost ends 12 days sooner than in Glendale, and it has 23 days more without frost. Its typical dates are January 8 and December 25, with 354 days frost-free.
• Scottsdale, AZ, 22 miles to the north-east: last frost January 27, first frost December 21, 330 days frost-free; the last frost is 7 days later than in Glendale, and the season is about the same length as Glendale's.
• Chandler, AZ lies 26 miles south-east of Glendale. Typical last frost February 13, first frost December 5, 298 days between; the last frost is 24 days later than in Glendale, and it has 33 days less without frost.

Next steps for Glendale gardeners

To go beyond the crops above, use the spring planting planner and fall planting planner, both set to this station. The frost dates tool shows the full odds for Glendale, and the hardiness zone lookup gives the winter-cold zone for your ZIP code.

Every city covered is on the city frost dates index, sorted by state.

Where these numbers come from

NOAA's U.S. Climate Normals for 1991–2020 (doi:10.25921/4ek7-fk11) supply every frost date here, unchanged from the station's record, and NOAA's documentation defines the probabilities. The Census Bureau's 2024 Gazetteer places Glendale on the map, and its Vintage 2024 estimates, 258,143 people here, decide which cities get a page.

The planting dates apply the count rules in University of New Hampshire Extension, NC State Extension and University of Georgia Extension to this station's dates, with nothing added. The methodology page explains how each figure is checked.

NOAA's dates say how often frost has come, not when it will. Check the forecast before planting and keep a cover on hand.