Frost dates 2026–2027

Frost dates for Upland, California

Most years have no 32°F freeze at Ontario Intl Airport, 5.3 mi away (close match), according to NOAA 1991–2020 climate normals.

Freezes are rare here
Last spring frostRarefewer than half of years
First fall frostRarefewer than half of years
Growing season365 daysbetween median 32°F dates
Hardiness zoneZone 10a30 to 35°F average extreme low

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Will it freeze in Upland in the next 7 nights?

No overnight lows at or below 32°F are forecast in Upland during the next 7 nights in the available NWS frost forecast.

Tonight: forecast low 55°F. Above 36°F.

NWS forecast period: Thu, Nov 5, 6:00 PM PST to Fri, Nov 6, 6:00 AM PST.

No nights at or below 36°F in the National Weather Service forecast for the next 7 nights.

Overnight lows from the National Weather Service forecast for this location. This covers the available forecast window, not the first freeze of the whole season. Frost can form above 32°F on clear, calm nights.

Frost and freeze probabilities

Freeze dates shift from year to year. Spring percentages describe the chance of a freeze after the stated date; fall percentages describe the chance of a freeze by that date. The 10% spring date is the cautious one: a later freeze happens about 1 year in 10.

These dates describe historical probabilities, not this year’s forecast or the earliest and latest possible freezes. Different weather stations or probability thresholds can produce different published dates for the same city.

Average first hard freeze in Upland

Most years have no 28°F hard freeze at Ontario Intl Airport, according to NOAA’s 1991–2020 Climate Normals. Check the short-term forecast above during cold snaps.

TemperatureLast spring date
90% · 50% · 10% chance of a later freeze
First fall date
10% · 50% · 90% chance of an earlier freeze
Season
36°F frost possible Dec 24 · Jan 27 · Feb 28 Nov 27 · Dec 17 · Jan 17 327 days
32°F freeze Dec 14 · Jan 4 · Feb 7 Dec 11 · Dec 30 · Feb 1 365 days
28°F hard freeze rare in most years rare in most years 365 days
NOAA NCEI U.S. Climate Normals 1991–2020, station USW00003102. The median 32°F growing season here is the whole year: most years have no freeze. How to read these probabilities.

Average high temperature by month

1991–2020 normals at Ontario Intl Airport

Average low temperature by month

Months with lows near or below freezing carry frost risk

Where these frost dates come from

The frost dates for Upland, CA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Ontario Intl Airport (station USW00003102, elevation 949 ft), 5.3 mi from Upland. Local conditions (valleys, hilltops, distance to water, city heat) can shift frost dates by days or weeks. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map (USDA ARS and Oregon State University PRISM). See our methodology.

Frost dates near Upland

CityDistanceLast spring frostFirst fall frost
Claremont, CA 3.1 mi Jan 8 Dec 28
Montclair, CA 3.7 mi Jan 8 Dec 28
Rancho Cucamonga, CA 5.6 mi rare rare
Ontario, CA 6.2 mi rare rare
La Verne, CA 6.2 mi Jan 8 Dec 28
Pomona, CA 6.8 mi Jan 8 Dec 28
San Dimas, CA 8.7 mi Jan 8 Dec 28
Chino, CA 9.9 mi Jan 17 Dec 19
Glendora, CA 11 mi Jan 8 Dec 28
Fontana, CA 11 mi rare rare

Frequently asked questions

When is the last frost in Upland?

Upland doesn’t reach 32°F in a typical year, according to NOAA’s 1991–2020 normals for the nearest station.

When is the first frost in Upland?

Freezes are uncommon here; check the 7-night forecast above during cold snaps.

Can it frost in Upland after the last frost date?

Yes. Frost can form on clear, calm nights even when the air stays above 32°F. Temperatures of 36°F or lower, cold enough for frost on exposed plants, have a 50% chance of occurring after January 27.

What growing zone is Upland?

Upland is in USDA Plant Hardiness Zone 10a (average annual extreme minimum temperature 30 to 35°F), based on the 2023 USDA map for ZIP code 91786. See growing zones in California.

More: all California frost dates · California growing zones · UV index today in Upland · frost vs. freeze