Harman US

Frost Dates for Belen, NM

Last spring frost
Apr 23
First fall frost
Oct 21
Growing season
178 days
Hardiness zone
7b

In an average year around Belen, NM, the last spring frost (32°F) is about Apr 23 and the first fall frost is about Oct 21, giving roughly a 178-day growing season. To be safe most years, wait until Apr 9 before setting out tender plants.

Last spring frost

Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.

Last spring frost - Belen, NM
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) May 16 May 3 Apr 22
Freeze (32°F) May 6 Apr 23 Apr 9
Hard (28°F) Apr 26 Apr 8 Mar 24
Severe (24°F) Apr 8 Mar 23 Mar 7
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F May 16 May 11 May 8 May 6 May 3 May 1 Apr 29 Apr 26 Apr 22
32°F May 6 May 1 Apr 29 Apr 27 Apr 23 Apr 20 Apr 17 Apr 14 Apr 9
28°F Apr 26 Apr 20 Apr 16 Apr 11 Apr 8 Apr 5 Apr 3 Mar 31 Mar 24
24°F Apr 8 Apr 3 Mar 30 Mar 27 Mar 23 Mar 19 Mar 15 Mar 11 Mar 7
20°F Mar 23 Mar 16 Mar 12 Mar 9 Mar 6 Mar 3 Feb 28 Feb 25 Feb 19
16°F Mar 11 Mar 5 Mar 1 Feb 26 Feb 22 Feb 18 Feb 14 Feb 8 Jan 31

First fall frost

Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.

First fall frost - Belen, NM
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Sep 30 Oct 10 Oct 23
Freeze (32°F) Oct 7 Oct 21 Nov 2
Hard (28°F) Oct 18 Oct 31 Nov 10
Severe (24°F) Oct 26 Nov 7 Nov 19
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Sep 30 Oct 3 Oct 5 Oct 8 Oct 10 Oct 13 Oct 16 Oct 19 Oct 23
32°F Oct 7 Oct 12 Oct 15 Oct 18 Oct 21 Oct 23 Oct 25 Oct 30 Nov 2
28°F Oct 18 Oct 22 Oct 25 Oct 28 Oct 31 Nov 1 Nov 3 Nov 6 Nov 10
24°F Oct 26 Oct 31 Nov 3 Nov 5 Nov 7 Nov 10 Nov 13 Nov 15 Nov 19
20°F Nov 5 Nov 8 Nov 12 Nov 14 Nov 17 Nov 19 Nov 21 Nov 25 Nov 29
16°F Nov 13 Nov 17 Nov 20 Nov 23 Nov 25 Nov 28 Dec 1 Dec 4 Dec 10

Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.

Where this data comes from

These dates are computed from the nearest official weather station with long-term records: Los Lunas 3 Ssw, Nm, about 9.9 miles away@if(!empty($station['elevation_ft'])), at 4,840 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.

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How we calculate these dates

Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.

Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.

Frequently asked questions

When is the last frost in Belen, NM?

On average, the last spring frost (32°F) around Belen, NM is about Apr 23. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 9.

When is the first frost in the fall?

The first fall frost around Belen, NM typically arrives about Oct 21. Count back by a crop's days to maturity to find the latest date you can plant it.

When can I plant tomatoes and other tender crops?

Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Apr 23 on average, or Apr 9 to be safe most years.

How long is the growing season here?

The frost-free growing season (between the last spring and first fall 32°F frost) is about 178 days in a typical year.

Are these dates a forecast for this year?

No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.

Local weather for 87002 Planting calendar → New Mexico frost dates →

Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026