Loveland, Colorado Frost Dates, Growing Season & Hardiness Zone
Frost odds and planting zone for Loveland for the 2027 season, based on 1991–2020 normals.
Last frost date
May 10
typical (50% chance of a later 32°F night)
Safer date: May 22 (10% risk)
earlyMay 10
typicalMay 22
safer
First fall frost
Oct 1
typical (50% chance it has happened by then)
Early-risk date: Sep 15 (10%)
Growing season
142 days
typical frost-free (32°F) season
Short year: 124 days (1 year in 10 is shorter)
USDA hardiness zone
5b
2023 map: -15 to -10°F average coldest night
2012 map: 5b
Stations around the metro don't all agree. The typical last frost is as early as May 2 at Fort Collins and as late as May 12 at Waterdale.
Half of years have their last 32°F night by May 10. In 1 year out of 10, a freeze still comes after May 22.
Based on NOAA station Loveland 2 N (USC00055236), 1.7 mi NW, elevation 5,080 ft (+80 ft vs. city center). Confidence: High.
When is the last frost in Loveland?
Expect the last 32°F night by May 10 in a typical year; 1 year in 10 still freezes after May 22. Cold 36°F nights (frost possible on plants) typically last longer, until around May 22. Hard freezes (28°F) typically end sooner, around May 2.
The typical date (May 10) and the safer 1-in-10 date (May 22) are 12 days apart. If you plant in between, you're taking a chance; watch the 10-day forecast.
Cool nights hang on after the last freeze: the typical last 36°F night (frost possible on plants in low spots) is around May 22, 12 days later than the typical last 32°F night. Frost can form on leaves on clear, calm nights even with the thermometer above freezing.
| Threshold | 10% (safer) | 30% | 50% (typical) | 90% (early) |
|---|---|---|---|---|
| 36°F (frost possible on plants) | Jun 4 | May 28 | May 22 | May 11 |
| 32°F freeze | May 22 | May 15 | May 10 | Apr 30 |
| 28°F hard freeze | May 14 | May 7 | May 2 | Apr 17 |
All probabilities (10–90%)
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F (frost possible on plants) | Jun 4 | May 31 | May 28 | May 25 | May 22 | May 19 | May 17 | May 14 | May 11 |
| 32°F freeze | May 22 | May 18 | May 15 | May 13 | May 10 | May 8 | May 6 | May 3 | Apr 30 |
| 28°F hard freeze | May 14 | May 10 | May 7 | May 4 | May 2 | Apr 30 | Apr 27 | Apr 23 | Apr 17 |
Is it safe to plant after Mother's Day in Loveland?
Many Loveland-area gardeners wait for Mother's Day to plant (CSU PlantTalk). In 2027, it falls on May 9. As of that date, the chance of another 32°F night is between 50% and 60%, and the chance of another 36°F night (frost possible on plants) is more than 90% (NOAA 1991–2020, Loveland 2 N).
Is it too early to plant in Loveland?
Before May 10 the odds of another 32°F night are better than even; after May 22 they are about 1 in 10 or less.
Today's risk is computed in your browser from the same NOAA probability table, shown as the range between the two nearest NOAA probability levels.
When is the first frost in Loveland?
By Oct 1, half of years have had their first 32°F night. In 1 year out of 10, it comes as early as Sep 15. In a typical year, look for the first 36°F night (frost possible on plants) around Sep 22 and the first 28°F hard freeze around Oct 10.
Fall plantings are timed backward from first frost: Oct 1 typically, or Sep 15 if you want a cushion. See the planting calendar for each crop's date.
| Threshold | 10% (early) | 30% | 50% (typical) | 90% (late) |
|---|---|---|---|---|
| 36°F (frost possible on plants) | Sep 8 | Sep 17 | Sep 22 | Oct 4 |
| 32°F freeze | Sep 15 | Sep 25 | Oct 1 | Oct 13 |
| 28°F hard freeze | Sep 22 | Oct 3 | Oct 10 | Oct 22 |
All probabilities (10–90%)
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F (frost possible on plants) | Sep 8 | Sep 13 | Sep 17 | Sep 20 | Sep 22 | Sep 25 | Sep 28 | Oct 1 | Oct 4 |
| 32°F freeze | Sep 15 | Sep 21 | Sep 25 | Sep 28 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 13 |
| 28°F hard freeze | Sep 22 | Sep 29 | Oct 3 | Oct 7 | Oct 10 | Oct 12 | Oct 15 | Oct 18 | Oct 22 |
How long is Loveland's growing season?
A typical year in Loveland has 142 days between the last spring and first fall 32°F nights. In about 1 year in 10, there are fewer than 124 days.
That's enough time for most warm-season vegetables if they go in on time. Long-season crops do best started from transplants.
Growing degree days measure the heat available for crops to grow. The station averages 2,510 a year (base 50°F).
| Threshold | 10% (long year) | 50% (typical) | 90% (short year) |
|---|---|---|---|
| 36°F (frost possible on plants) | 140 days | 122 days | 104 days |
| 32°F freeze | 157 days | 142 days | 124 days |
| 28°F hard freeze | 178 days | 159 days | 140 days |
How does Loveland's season compare?
Of the 20 Colorado cities with frost dates on this site, Loveland has a typical frost-free season of 142 days, which is the shortest.
None of the 56 U.S. cities with frost dates on this site has a shorter typical frost-free season than Loveland (142 days), and the season is longer in 55 of them.
Growing degree days (base 50°F)
Annual normal: 2,510 GDD (NOAA flag R, 24 years). Running total by the end of each month (sum of NOAA daily GDD normals, so the year-end total can differ slightly from the annual normal):
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 0 | 14 | 70 | 281 | 761 | 1,438 | 2,051 | 2,409 | 2,500 | 2,508 | 2,509 |
What growing zone is Loveland? (USDA 2023)
On the 2023 USDA map, Loveland is zone 5b (-15 to -10°F average coldest winter night). That's no change from the 2012 map.
| ZIP | 2023 | 2012 | Change | Share of ZIP in Loveland |
|---|---|---|---|---|
| 80526 | 5b | 5b | unchanged | 0% |
| 80528 | 5b | 5b | unchanged | 1% |
| 80534 | 5b | 5b | unchanged | 0% |
| 80537 | 5b | 5b | unchanged | 10% |
| 80538 | 5b | 5b | unchanged | 21% |
| 80550 | 5b | 5b | unchanged | 1% |
Other ZIPs touching Loveland
ZIPs outside the 805 prefix that overlap the city boundary:
- none
Zones: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed 2026-10-08. Shown as published in the ZIP tables; this page does not show a zone map. Not the official USDA Plant Hardiness Zone Map (official map: planthardiness.ars.usda.gov).
Does the new zone change Loveland's frost dates?
No. Hardiness zones are based only on the average coldest winter temperature. They say nothing about when spring and fall frosts happen. Loveland's frost dates come from NOAA's 1991–2020 frost probabilities, which did not change with the 2023 zone map. Use your zone to pick perennials that will survive winter, and your frost dates to time planting.
Why do Loveland frost dates differ between websites?
You may see May 15 given as Loveland's last frost date. That's the 30%-risk date, meaning about 3 years in 10 still have a 32°F night after it. Our headline date is May 10, the 50% (median) date.
The 'safer' date, May 22, is the 10%-risk date. A 32°F night after it happens in only about 1 year in 10.
May 22 is the typical (50%) date for a 36°F night (frost possible on plants), not a 32°F freeze. Any site that draws the line at 36°F will show later dates.
Station choice is another reason dates differ. Our 6 qualifying stations within 25 miles of the city center range from May 2 to May 12 for the typical (50%) last 32°F frost (table below).
| Date | What it is (NOAA 1991–2020) |
|---|---|
| May 15 | 32°F last frost, 30% risk (a 'balanced' date) |
| May 22 | 36°F last cold night, 50% (frost possible on plants) |
| May 22 | 32°F last frost, 10% risk (the 'safer' date) |
| May 2 | 28°F last hard freeze, 50% |
| May 2 | 32°F last frost, 50%, at Fort Collins (nearest station with NOAA flag S) |
| Station | Distance | Elevation | Typical last frost |
|---|---|---|---|
| Fort Collins | 11.1 mi N | 5,004 ft | May 2 |
| Greeley UNC | 19.2 mi E | 4,715 ft | May 2 |
| Fort Collins 4 E | 11.2 mi N | 4,920 ft | May 3 |
| Longmont 2 ESE | 17.1 mi S | 4,950 ft | May 7 |
| Loveland 2 N used here | 1.7 mi NW | 5,080 ft | May 10 |
| Waterdale | 7.8 mi W | 5,230 ft | May 12 |
Which weather station is this based on?
- Station
- Loveland 2 N (NOAA USC00055236, COOP)
- Distance
- 1.7 mi NW of the city center
- Elevation
- 5,080 ft; city center 5,000 ft (USGS), difference +80 ft
- Record
- NOAA completeness flag S, 25 of 30 years (1991–2020)
- Confidence
- High (rule)
Confidence: High. The station is 1.7 miles from the city center, only 80 ft different in elevation, and its frost statistics meet our completeness rule (NOAA flag S, 25 of 30 years).
| Station | ID | Distance | Elev. (Δ) | Last frost 50% | First frost 50% | Season 50% | NOAA flag / years |
|---|---|---|---|---|---|---|---|
| Loveland 2 N | USC00055236 | 1.7 mi NW | 5,080 ft (+80) | May 10 | Oct 1 | 142 d | S / 25 |
| Waterdale | USC00058839 | 7.8 mi W | 5,230 ft (+230) | May 12 | Oct 1 | 141 d | R / 23 |
| Fort Collins | USC00053005 | 11.1 mi N | 5,004 ft (+4) | May 2 | Oct 7 | 157 d | S / 29 |
| Fort Collins 4 E | USC00053006 | 11.2 mi N | 4,920 ft (-80) | May 3 | Oct 6 | 154 d | S / 29 |
| Longmont 2 ESE | USC00055116 | 17.1 mi S | 4,950 ft (-50) | May 7 | Oct 5 | 151 d | R / 17 |
| Greeley UNC | USC00053553 | 19.2 mi E | 4,715 ft (-285) | May 2 | Oct 8 | 159 d | S / 25 |
Other stations within 25 mi (not used)
- Buckhorn Mountain 1 E (USC00051060), 18.4 mi NW, 7,400 ft: typical last frost May 21. Not used: |elev diff| 2400 ft > 500 ft.
- Estes Park 3 SSE (USC00052761), 24.5 mi W, 7,812 ft: typical last frost May 30. Not used: |elev diff| 2812 ft > 500 ft.
80 other NOAA normals stations within 40 km (mostly rain gauges) have no frost statistics.
Loveland planting dates at a glance
Balanced dates use the 30%-risk last-frost date as the anchor. The Loveland planting calendar has typical and safe dates, fall planting and a month-by-month list for 27 vegetables.
| Crop | Start indoors | Plant outdoors (balanced) | Fall |
|---|---|---|---|
| Tomatoes | May 9–23 | Jun 27 | – |
| Peppers | Apr 3–17 | May 29 | – |
| Potatoes | – | May 1–15 | – |
| Onions (dry, from sets) | – | Apr 17 – May 1 | – |
| Peas | – | Apr 17 – May 1 | sow by Jul 14 |
| Lettuce (leaf) | – | Apr 17 – May 1 | sow by Jul 19 |
| Carrots | – | May 1–15 | sow by Jul 9 |
| Beans (snap) | – | May 15 | sow by Jul 5 |
| Summer squash | – | May 15 | sow by Jul 15 |
| Broccoli | Feb 27 – Mar 13 | Apr 17 – May 1 | transplant by Jul 14 |
| Cabbage | Feb 27 – Mar 13 | Apr 17 – May 1 | transplant by Jun 24 |
| Cauliflower | Mar 13–27 | May 1–15 | – |
| Kohlrabi | – | Apr 17 – May 1 | sow by Jul 29 |
| Green onions | – | Apr 17 – May 1 | sow by Jul 19 |
| Radishes | – | Apr 17 – May 1 | sow by Aug 18 |
| Spinach | – | Apr 17 – May 1 | sow by Aug 8 |
| Turnips | – | Apr 17 – May 1 | sow by Jul 29 |
| Beets | – | May 1–15 | sow by Jul 19 |
| Swiss chard | – | May 1–15 | sow by Jul 19 |
| Parsnips | – | May 1–15 | – |
| Sweet corn | – | May 15 | – |
| Cucumbers | – | May 15 | sow by Jul 10 |
| Eggplant | Mar 27 – Apr 17 | May 29 | – |
| Cantaloupe | – | May 29 | – |
| Watermelon | – | May 29 | – |
| Winter squash | – | May 29 | – |
| Garlic | – | – | plant Oct 1–14 |
When to plant tomatoes in Loveland · Fall planting dates for Loveland
Frost dates near Loveland
| City | Distance | Last frost | First frost | Season | Zone 2023 |
|---|---|---|---|---|---|
| Fort Collins frost dates | 9 mi | May 2 | Oct 7 | 157 days | 5b |
| Greeley frost dates | 15 mi | May 2 | Oct 8 | 159 days | 5a–5b |
| Longmont frost dates | 17 mi | May 7 | Oct 5 | 151 days | 5b–6a |
| Boulder frost dates | 29 mi | May 6 | Oct 5 | 151 days | 6a |
| Thornton frost dates | 35 mi | May 2 | Oct 11 | 160 days | 6a |
| Commerce City frost dates | 40 mi | May 3 | Oct 7 | 155 days | 5b |
Frequently asked questions
What is the average last frost date in Loveland?
May 10 is the median (50%) date for Loveland's last 32°F night, from NOAA 1991–2020 normals at Loveland 2 N. To play it safe, use May 22: only about 1 year in 10 has a freeze after it.
When is the first frost in Loveland?
The first 32°F night typically arrives by Oct 1. About 1 year in 10, it comes as early as Sep 15. A 36°F night (frost possible on plants) typically shows up around Sep 22.
What growing zone is Loveland, Colorado?
Loveland is USDA hardiness zone 5b. The 2023 map kept it in the same zone as the 2012 map.
Is it too early to plant in Loveland?
If it's before May 10, it's too early for frost-tender plants: another 32°F night is more likely than not. From May 10 to May 22, the risk falls from 50% to 10%. Cool-season crops such as peas and lettuce can be planted weeks earlier (see the planting calendar).
What temperature is a killing frost?
For tender crops like tomatoes, a light frost is a killing frost. CSU Extension calls 28–32°F a light frost and below 28°F a heavy frost. Our NOAA odds cover three thresholds: 36°F (frost possible on plants), 32°F (freeze, our headline) and 28°F (hard freeze).
Is first frost the same as first freeze?
Not exactly. A freeze is about the air reaching 32°F. Frost is ice on surfaces, which can form on calm, clear nights while the air is still a few degrees above freezing. So in Loveland, the first 36°F night (frost possible on plants) typically comes around Sep 22, ahead of the first 32°F night (Oct 1).
Download & sources
- Add Loveland frost & planting dates to your calendar (.ics, 2027)
- Printable planting calendar (PDF)
- How these numbers are calculated
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (annual/seasonal and daily normals, station USC00055236); USDA Plant Hardiness Zone ZIP tables 2023 and 2012 by the PRISM Group, Oregon State University; Census 2020 ZIP/place relationship file; USGS elevation. Long-term odds, not a forecast. Figures and sentences are generated from these data by fixed rules; see the methodology. Last updated 2026-10-08.