When to plant in Berthoud, CO
USDA Zone 5bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Berthoud, Colorado — all computed from Berthoud's nearest NOAA weather station.
Heads up: the nearest complete-normals station is about 16 km from Berthoud, so your yard's frost dates can differ — a low spot or a paved city center can shift them by a week. In zone 5b, Berthoud gardeners can grow many hardy perennials, while the last and first frost still dictate the annual vegetable calendar.
The average first fall frost in Berthoud is now 8 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
LONGMONT 2 ESE · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Berthoud’s own odds, recorded at LONGMONT 2 ESE.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Jun 2 | May 18 | May 5 | Sep 14 | Sep 28 | Oct 8 |
| 32°F | May 22 | May 7 | Apr 24 | Sep 23 | Oct 5 | Oct 16 |
| 28°F | May 12 | Apr 28 | Apr 11 | Sep 30 | Oct 12 | Oct 25 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Berthoud, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 26 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Berthoud planting FAQ
When is the last spring frost in Berthoud, CO?
Berthoud's average last spring frost falls near May 7 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Berthoud, CO?
In Berthoud, the first 32°F freeze of fall lands around October 5 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Berthoud in?
Berthoud is in USDA hardiness zone 5b. In zone 5b, winters are cold — pick cold-hardy varieties and protect tender crops.
How long is the growing season in Berthoud?
Berthoud has about 151 frost-free days — a moderate growing season — between the average last spring frost (May 7) and first fall frost (October 5).
When should I plant tomatoes in Berthoud?
For Berthoud, sow tomatoes indoors about March 12–March 26 and move the seedlings out around May 14, after the last spring frost.
Never miss a window in Berthoud
An email when it’s time to start seeds, transplant, and sow — timed to Berthoud’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at LONGMONT 2 ESE, 16 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Berthoud, CO — Frost Dates & Zone 5b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00055116. Retrieved from https://blissgarden.com/colorado/berthoud.